I would also take the chance to say I think this is one of a few reasons why you shouldn't store any sensitive materials (bank statements, tax forms, etc.) directly on your machine unless they're securely encrypted. Forget to erase a hard drive, take a computer in for repair, have your computer stolen, a number of different potential situations where something could happen.
I like the idea of keeping everything of that nature on a Flash drive, because then you can keep it in an area totally separate of your computer stuff when not in use, reducing the chance of it being stolen if somebody is just grabbing a handful of equipment. Also, you can then put it together with any other items you have prepared to quickly be grabbed in case of fire or other emergency.
At the least, though, keep important documents on your machine in some sort of encrypted fashion. There's no excuse not to do this on a Mac, because you can quickly and easily create an encrypted disc image than can be mounted or unmounted as needed.
As for web stuff, as others have said, get to changing your passwords ASAP. Even if your browser keeps a session active or password in memory, that'll help protect you.
