Another vote for the password manager approach. My IT friends generally use Keepass or Password Safe- free and easy to use.
We store our password databases somewhere on the cloud (Amazon S3/Jungledisk, Dropbox, Sugarsync) so the databases are updated and accessible from multiple trusted computers (work, personal laptop, home). I also keep my database on a USB stick on my keyring in case I really need to access it from somewhere in an emergency. Some of these packages will allow for boot-to-USB so you can boot into a known safe OS instead of using hotel/internet cafe computer which probably has all sorts of dodgy crap loaded onto its hard drive.
The good thing about cloud storage for the password database is that you get automatic backups and the ability to roll back to previous versions if you corrupt the file. You can also backup simply by mailing the database to yourself occasionally.
Regarding the issue of forgetting the master password... well, you'd have to be a bit thick to do that as 1) you only have one password to remember instead of twenty and 2) it's a bloody important one so it should be strong and easy to remember (see Pin's cartoon). Or as a last resort, you store the master on paper, in a safe.