I have a unique, random password for nearly every account I have (with a few throwaway exceptions). I store them all in a file, encrypted with a master password, and sync that file to all my machines using Dropbox. I open and modify the file with Password Gorilla on Mac and Linux and PasswordSafe on Windows.

Both programs read/write the same file format and allow you to create any internal hierarchy you want (eg Stores > Electronics > NewEgg, or News > HackerNews). Password Gorilla's UI is pretty bad, but workable. Both let me copy and paste a password without displaying it on screen.

Works great. I got the idea from Joel Spolsky: http://www.joelonsoftware.com/items/2008/09/11b.html