For multi-platform I'd guess it's good. Only bad thing I see is that it encrypts individual files, they are not hidden at all, while tools like Safeguard allows to mount once and use it like a normal drive.
Well I guess a solution would be to use both? For windows related and wanting hidden files, use USB safeguard, and then for cross platform things that you may want to access on a nix system, say an automated bash script to own a n00bz box could work
Also another easy solution would be hardware encryption. Are you looking for a specific type of encryption? AES 256bit, PGP, etc
This seems to be a pretty good one:
http://sourceforge.net/projects/freeotfe.mirror/Features:
Highly portable - Offers a portable mode, eliminating the need to install to the computer, there is also FreeOTFE Explorer; a system which allows FreeOTFE volumes to be accessed without installing software, and on computers where no administrator rights are available.
Easy to use - A full wizard is included for creating new volumes.
PC and PDA versions available. Encrypted data on your PC can be read/written from your PDA and vice versa.
Support for encryped Linux volumes (Cryptoloop "losetup," dm-crypt, and LUKS).
Available in multiple languages.
Optional support for smartcards and security tokens.
Powerful - Supporting numerous hash (including SHA-512, RIPEMD-320, Tiger) and encryption algorithms (Including AES, Twofish, and Serpent) in several modes (CBC, LRW, AND XTS), providing a much greater level of flexibility than a number of other OTFE systems.
Encrypted volumes can be file, partition, or disk based.