Won't help now, but the Keychain is a great place for storing that sort of info.
Whenever you get a license #, especially for any sort of download only software, open up Keychain and create a 'Secure Note'. I do this for all sorts of data, including all user names and passwords. For passwords, I create the Secure Note with user name and password, then copy and paste from there to wherever it is I'm registering.
Since Tiger, after a fresh install of the new OS, I've been able to just replace the login keychain with my backup copy from the old OS and keep going as if nothing happened in relation to auto logins, etc. You'll have to reauthorize some apps to access the keychain, but that's about it.
Even if someone gets hold of your notebook logged in already, all access to the Keychain data still requires your master password.
Also, if you're only keeping DVD info, no books, games, etc.; you might want to give DVDPedia a try. It's a nice piece of software also and save ya $20. And, it will auto import your Delicious Library.