Thanks for the input, MobileMe seems like a sound option for keeping some files and what not over the web. The reason I originally posted was because I'm beginning to fret that my 250 HD isn't big enough for what I'm going to need in the future for school. Now that I realize my university doesn't allow new wireless access points (thanks scarboni21), I probably won't be able to take advantage of all of the TC's features...but then again, when I take it home (from my university) I could use it more efficiently there. Decisions, decisions...
I was in the same boat as you, now mind you I am not at University, and I have multiple computers, but I needed a way to back up my data. I would not suggest going the Time Capsule route as the majority of universities will not allow you to plug it into the network, however, you could just set up a network and connect to it when you want to back up, if you don't want to have to plug in a cord??? (but you have to plug in to charge anyway)
I do the following two things:
1. Buy a firewire hard drive (not from apple) about 3 to 4 times the size of your hard drive and partition it to as many partitions as you want, but at least two. One for Time Machine, and One for Scratch, spare space in case you ever need it. This way you don't have to reformat and lose your Time Machine back up down the line. (You could also partition it three ways and make a clone of your hard drive periodically since I have heard Time Machine backups don't always work.)
Now that you have those partitions set up your Time Machine back-up to one of the partitions (Also if you haven't already rename it, esp. if you made multiple partitions.) Then let it do it's initial back-up. Then from that point on plug it in once a week, once a month, or however frequently you would like, but do it at night when it is charging (since you have to plug it in at some point anyway) and let it do its backups.
2. Download DropBox. It is free, up to 2 gigs, and it will keep a copy of the data online, and on your computer (multiple computers if you have them). It works great, relatively quick, and keeps multiple back-ups on the web version. So, what I do now if for any current project, or current class keep that information in my dropbox folder, which syncs online, and can be accessible from any computer online. This items sync any time they change (provided you are online, or they will sync the next time you go online).
So, this way you have a long term back-up that you do periodically, because quite frankly for the average user the hourly or 30 minutes backups time machine does it overkill and waste resources. And then you have the dropbox backup for daily current project backups.
I do this with one large firewire hard drive for my desktop and laptop all on the same drive. (I also have a cloned copy of my laptop drive I update periodically on another drive using the free carbon copy cloner.) And I also have a scratch space on the drive for big projects occasionally, but I rarely use it. If you buy a quality drive you shouldn't have any problems.
My university doesn't allow us to have wireless routers either... but err, I kinda have one anyway, and I'm not alone. I just have the good sense to not broadcast my SSID unlike my peers!
Just an FYI, they don't figure out you have a router from your SSID being broadcast . . .