Forgotten passwords

I am so bad at remembering the passwords and usernames and things that I use for the many sites I visit that require a login (mostly messageboards). Usually I use the same one with a few different variations, but there are some sites with weird username/password requirements and those are the ones I can never remember. I need some kind of keylogger or password manager or something to keep track of what I put in. Oh wait, I guess my browser does store most usernames and passwords, but for some reason it doesn't on some sites. I really should just write them down somewhere or save them in a file.