Once upon a time, prior to the advent of digital media, photographic archiving meant putting your negatives in the cupboard. Your negatives had to be kept safe from the evils of cigarette smoke,, humidity, uv light, finger marks, hot coffee cups, acid, coughs and sneezes, chain saws, and so on. If you left them alone they would be fine for future reproduction for the duration of the average human lifetime without any significant loss of detail or tone (film stocks varied in longevity).
Barring fire, flood or the inquisitive hands of young children, your negatives would be well disposed for future printing and unless you happened to be in charge of some national archive of precious photographs, the negative archiving story ends here.
The digital era has re-introduced the same concerns over storage only this time the number of options are plentiful and growing all the time. The great advantage that digital images have over their analog antecedents is that they can be copied indefinitely without any loss of quality. This flexibility of duplication allows us to store our images on several different devices. Storing your images on at least two separate devices is essential to avoid loss of data. Image data is often irreplaceable; you may be able to re-shoot, re-design, or re-edit your images but they will never be the same as the originals and the amount of work involved in starting afresh may cause you to abandon your endeavors entirely.

CD-ROM & DVD ROM
The optical storage flag is currently flown by CD-R and DVD-R discs. The advantages of these discs is that they are so cheap that you can make several copies of your data without having to even consider the cost. The disadvantage of this means of storage is their susceptibility to damage; one scratch and the disc can become unreadable. Secondly and more important is the question their longevity. The data is stored in a layer of dye that lies behind the transparent underside of the disc. The binary data of your files are recorded by burning holes through this dye layer by means of a laser in your CD/DVD burner. The problem with the dye is that, on this scale, the dye can be thought of as a liquid, the holes will be gradually filled in by the surrounding dye and your data will cease to exist. Currently you should only expect a year or two from DVD storage and perhaps four years for a CD. These discs should not be relied upon as the sole storage medium for your archive and should be treated as temporary measure.
Blue Ray is the latest advancement in optical storage technology but we won't consider this as a sensible means of storage until the home computer variation of the technology has proved to be a stable means of long term storage. With this option you can expect the same results as with early CD-R and DVD-R media and burners where results were arbitrary at best.

Hard-Drive
Magnetic storage devices have been around since the dinosaurs roamed the earth and have therefore had sufficient time to have evolved into the fast and efficient creatures they are today. The capacity and cost of hard-drives makes them most attractive medium for archival purposes and its reliability is without equal. So where's the rub?
The major problem with relying upon the hard-drive is that it's convenience, seamless integration, high capacity and reliability encourage a high degree of complacency in the mind of the user. You can be fooled into thinking that your hard-drive is infallible, but one day you will switch-on your computer and it will fail to boot. This will be the day that your hard-drive died. There are data recovery companies who will try to recover data from damaged drives, but you may have to sell some of your organs to pay for it. Relying on a single drive is foolhardy and the obvious solution is to have a second drive that you can use to backup your archive on a regular basis.
USB drives are a convenient option as all you have to do is plug the device into any free socket. They usually come pre-formatted so you can use them straight out of the box.
A hard-drive system that does this backup automatically is the RAID-1 Array. The RAID system consist of two or more internal hard-drives that, when set-up for RAID-1, will write all of your data to both drives simultaneously. If one drive fails on a RAID-1 system the data still resides safely on the other drive. Your computer motherboard must support RAID if you intend to use this method.

Flash Ram
USB memory sticks and the plethora or memory cards that we use in our cameras and telephones all rely on flash memory. This type of memory is suited to portable devices and can last for 100.000 re-writes (according to manufacturers). It's suitability for archival purposes is limited due to the relatively small capacities of the units. They're ideally suited to short-term portable storage and represent the most efficient means of transferring gigabytes worth of data from one device to another. Performance issues may occur if the memory is allowed to become fragmented. Their are rumors that using fragmented cards can lead to permanent damage, though this is not universally accepted. De-fragmenting your card or re-formatting when you've transferred your data to the archive will ensure that you get the best performance and life span from your memory.
Hundreds of millions of flash ram units are shipped from the far east each year and there are some concerns that quality control has dropped as a consequence of this increased production. These concerns however seem to be emanating from the more established manufacturers and can be seen as an attempt to dissuade consumers from opting for the cheaper cards. A queries via any search engine will reveal any public or industry concerns over a particular manufacturer and it may be wise to do this if you are considering purchasing an unfamiliarly branded product.

Online Storage
Theft should be your biggest concern if you have your files stored in a single geographical location such as your office or home. If a thief cleans out your office you could loose your computer, CD folders, memory cards, external/network drives and your laptop. This will leave you with nothing. A year's work or even worse, your entire archive could be irretrievably lost.
Most thieves will not be concerned with the contents of your hard-drive and are only interested in turning your equipment into ready cash. The person who ultimately buys your stolen computer may suffer a minor pang of guilt as he re-formats your hard-drive but that would be no consolation to you. Your files have gone in order that some itinerant junkie can stick a needle in his arm, or the suspicious looking old lady that lives next door can buy a solid gold litter tray for her favorite cat.
Now that we have established that it's a sick world we live in, let's assess how we might combat the risk of this consequential loss of data.
The only way you can beat the criminals is to store a back-up of your archive at an alternative site. For the sake of  convenience this site should be an online storage service. You can simply rent some space on a web server and use it to back-up all of your archive and even upload your daily or weekly output. Once this is accomplished your files are safe. Even if someone should steal all of your equipment you could then download your archive back from the online server and carry on where you left off (once you'd bought a new computer, graphics tablet, monitor, and anything else that hadn't been nailed down). The price of computer equipment though, is relatively small compared to the cost of loosing years of work.
There are plenty of companies offering online storage and it wouldn't be fair to recommend any one in particular, but some of them offer a few gigabytes of free storage so that you can try out their service and they allow you to download their client software that makes uploading and downloading files as straightforward as possible. A simple search via Google will reveal a plethora of options and you should find the most suitable one for your requirements.
If you have your own web site, hosted remotely, then you could, of course, utilize your own server space.

In conclusion
Use your flash cards to transfer your files to your workstation and from there backup your material to your online server space. Using this set-up you will not lose any of your data. Uploading your new files to the server should be a part of your daily routine and any loss of data suffered as a result of your failure to do so will be your own fault.