For backups of documents (this isn't exactly security related), I use SpiderOak. You set up watch folders, it keeps track of the changes, and uploads your files to their servers. It uses an encrypted connection, and all your files are encrypted on their servers (The SpiderOak team can't access/read your files). You get 2GB free, and it has nice features like syncing folders between computers, and doing file rollbacks.
To keep track of all my passwords, I use KeePass. Works on Mac, Windows, and Linux. It stores passwords in an encrypted database. You only have to memorize one passphrase to access all your passwords, so it makes it easier to use different strong passwords for every different account you may have. I use SpiderOak to sync the password database between multiple computers.
Tor is a great anonymizing network for things like web browsing. But, it's not "secure" in some sense. While using Tor, never log into any site, because the exit nodes can sniff your traffic, and perform man-in-the-middle attacks.
TrueCrypt is a very good file encryption system. It even allows the use of a decoy and hidden encrypted file system in the case plausible deniability is needed.
Browser plugins for FireFox like HTTPS Everywhere, Ghostery, Better Privacy, and NoScript can also help enhance privacy and security.