Fireproof safes are not rated forever... more like 20-60 minutes and even then your stuff inside is not 100% safe.
Some "media" safes say that you can store CD's or DVDs but I sure wouldn't trust them.

CD's and DVD's may rot or crack but I've got some that are 10yrs old still working fine and I make backups monthly so new cd/dvd a month = long long time before it ever cracks or dies. Those thumb drives are great and they are getting bigger and cheaper every day. I think you can get 4gb ones for around $120 now!!

Any backup is better than none <img src="/images/graemlins/wink.gif" alt="" />