This is an awesome solution. I have been using it for a couple of years now and have introduced it to a lot of people. Basically create one strong password that you can remember, it creates a nice encrypted file for you, lets you sort and group your passwords (i.e. Internet, Banking, Network, and lets you add custom groups). Then you can have it perform auto-type where it switches to the last window and types the username > tab > password (you can also use scripting if you need it to do some other variation for a particular site), or copy just the username or password with an auto-clear memory so your password doesn't stay in memory.
Keepass works Windows, Linux, and Mac. I don't have a Mac, but it runs on all my Linux and Windows machines. And because it is encrypted, you can throw it on a jump drive, or something like SkyDrive so you can access it from anywhere. You can even install Keepass on your jumpdrive with the no-installer version so you have a total portable solution.