This applies to you, whether you work in a large company where the server is backed up regularly, or if you are a one to ten person operation. If your computer gets fried or, as happened to me, the motherboard went, where is your data? Yes, a server might back up your data if you are on a big network, but what about your "C" drive?
I'm looking at you, because we have all done it. Quickly saving something on the computer's hard drive instead of the network so we can go back and refine something or just because we are in a hurry. In a big operation, your computer's own storage is not protected. Remember, large companies run most of their software on a server or two and the data you provide is stored there too. Anything "off-road" is vulnerable.
If you are completing something personal at work (yes, yes, I know - we aren't supposed to but most people do anyway), back it up to a data key at night or email it home to yourself at the end of the day. Five minutes will save you a lot of frustration.
If you are a small company and your computer goes down, make sure you have your original installation disks and serial number in one place. It will save you a lot of grief later. Don't be fooled and think "I don't have anything important on my computer." It may not be life-saving information, but it would be really annoying to lose it.
Just remember, "fries with that" is not an option.