Oh, man--there isn't really a good answer for this one. I've heard of the baking process, too, but we haven't had to do it with any of the tapes at work (I work in an archive). My bosses are still firmly in the cassette tape camp and I realize that CD's and MP3's are still risky, but I, personally, don't see that there is a "best answer" right now.

The argument that my supervisor makes is that CD and CD player technology runs the risk of becoming obsolete, but I don't see how that doesn't apply to cassette and tape deck (VHS, whatever) technology, also. Tape decks do wear out. Tapes can get crud in them and stick, or can be magnetized and erased by accident.

I've still got stuff on cassette and have been converting to digital but keeping the cassettes. Hopefully somebody will come up with something more reliable soon.