I've never used File Vault, What are the needs why one would bother? Joe Kissel has an entire PDF book on it...
Given laptop's propensity for growing legs FileVault is IMHO essential to protecting your identity and data from "the bad guys'". For all computers that connect to the internet it is an additional layer of data protectionism from exploits.
If we knew what it was we were doing, it wouldn't be called research, would it?
