Cross platform file encrypt/decrypt software?

[JEBB]

I want to be able to encrypt files on my netbook with Ubuntu 9.04 UNR and on my MacBook (Mac OS 10.6.2) and be able to exchange them and decrypt them on the other platform.

The Ubuntu command Edit>Encrypt is so easy to use but works only on the netbook. I haven't, thus far, found a program to open them on the Mac or to create an encrypted file on the Mac that I can open on the netbook. Anyone know of a program common to both that will do what I want? Thanks.

[RedSingularity]

Have you seen truecrypt? Thats what i use. Excellent program.

[JEBB]

Truecrypt seems not to encrypt individual files but entire volumes. Any other suggestions?

[bodhi.zazen]

For single files you could try gpg.