security software

Hey.
Does anybody know or has used this 2 encryption programs?

** http://www.dekart.com/howto/howto_disk_encryption/encrypt_flash_drive_cd...
** http://www.cypherix.co.uk/cryptainerle/online_help/index.html

They claim that they dont need any Admin privileges in Windows, and they run straight from the flashdrive.

How would using this utilities affect the performance of portable apps, suchs as Thunderbird Portable?

Thanks a lot for your comments- Sergio