I used a FreeBSD box to setup Racoon and friends and wound up with a pretty decent setup that used certificates for logging in and was compatible with the built

I used a FreeBSD box to setup Racoon and friends and wound up with a pretty decent setup that used certificates for logging in and was compatible with the built in OS X VPN support (L2TP + IPSec). The resulting solution is painless enough to deal with that I use it whenever I'm on wifi, even at home. You pay the price with a pretty complicated setup (assuming you're not already an IPSec guru, which I certainly am not), though.