Encryption Program Suggestions

Just switched from XP to Win 7 64 bit on my Desktop Computer. I'm looking for a simple, trustworthy, Encryption program to encrypt/decrypt the contents of an external USB or thumb drive that will work with both XP (for my laptop) and with Win 7 64 bit.
It would also be nice if that same program could encrypt/decrypt specific files or folders on the hard drives but the external USB drive is my primary concern.

I was using Cryptosuite with XP and that has always worked GREAT but I dont believe it's compatible with the Win 7 64 bit OS. But then I am a bit confused, the company that sells crytosuite (Ghost Security) says its compatible with 64 bit XP. Does that mean it will work with 64 bit Win 7 XP ???? Of course it handles all file systems but I only use NTFS at this point.

From what I have read on these forums nobody has had anything but trouble with BitLocker to Go. All I want is a program that lets me choose the drive to encrypt, asks me for a password and then does it's thing. Nothing too fancy. Just reliable.

But I'd like to be able to use it with my XP laptop as well as my Win 7 desktop
It dosent have to be a free program.

Any ideas from all you guys ???????