some admin tools / partitioning tools include an encrypted filesystem option besides that you have PGP if you look for any reason for a commercial encryption - then a Google search for harddrive encryption tool will give you results do you have a particular reason NOT to use the free PGP ?
Truecrypt is your best option but with seperate keys. Put the keys onto USB disk and DONT EVER copy them to your hdd. Also, if you are looking for paid encryption application - Whats your budget?
Well, Truecrypt is a good suggestion But still Desksense is doing best in this field .. Their DEMO version is FREE, it has folder lock,encryption,password protected, websites block, USB lock and few more like file splitter, merger and shredder .. So here you can also go with Desksense.com .. Again, no worry about the prices .. The Maximum value of this s/w is just $14.99 Only.. Just accurate to your budget I think
Try these results from google; Some good enterprise level encryption tools available for download; http://www.google.co.nz/search?q=enterprise+encryption+tools
i have free encryption tools, i think..that is good app. if you want..you can visit this site.. http://jogjafree.com or http://jogjafree.net regards! Noctis [ http://superhacker.org ]