PGP

Excellent! Thanks for taking the time to test this!! BTW, how secure is AES?? Vague question, I know, but relative to say PGP?

PGP (or GPG) could be used, but it'd be unnecessarily complicated. You'd have to unencrypt a file to work on it, then reencrypt it when you're done... The solution: Make a disk image. Go into Utilities and go to Disk Copy. Make a new image big enough to fit all the files you need encrypted on, and select the encryption option. Now you'll be asked for the passphrase...

Check versiontracker for "encryption" and "pgp"

BTW, I suggest using GnuPG as your PGP system. ...

A preferences pane in system preferences that gives you additional controls over your PGP system. Handy, and well presented. ...

Arhh, so CryptoHeaven is a 2nd party then. ;) Oops. Usually after two parties I have a little trouble paying attention to details. And, to be perfectly honest, my initial impressions of CryptoHeaven are based on the web site, which seems to have quite a lot of advertising on it. Okay, so you have to make money somehow, and you are providing a free service, but it...

Okay, how is CryptoHeaven NOT a third party? There is the person sending an encrypted document, the person recieving it, and CryptoHeaven. One, two, three. If I use the .pgp.net network, thats a third party. So is CryptoHeaven, they're just using a linguistic technicality to try and impress people who have little understanding of public-key encryption. It is a marketing...

also, any downloads that take me to a cgi or pgp script, I cant seem to download at all.. ...

How about gnumail? It's Cocoa, supposedly has proper filter support (unlike Mail.app), and supports PGP. http://www.collaboration-world.com/gnumail/ Don't really know what features you're after. Personally, I want a mail app that's not got too many features - nice and small. Mail.app is nice and small, but has the wrong few features for me...

I'm voting for Mail.app, mainly because it integrates perfectly with GnuPG (A PGP encryption implementation available for OS X) and handles HTML rather well.