Have you ever cried when you left your USB stick on a computer in the lab to discover it missing when you came back 25 minutes later? Has your external hard drive failed with all your work on it?
Welcome to 2010! Fortunately there are a few ways to have instant backup of and online access to your data and files. Microsoft’s mesh (5gb) and Dropbox (4?), both offer painless backup of your important work folders; you select the important folders, and the software does the rest.
And if you want to get fancy and have a multiple computers (say a netbook and a desktop) then you can have your work synced across computers multiple computers, with instant-changes registered on both.