It's possible but requires a little bit of patience to figure out and go through all of the steps. You may be very willing to go through the steps, but the other person might not.
First thing you'll need to do is install some sort of IRC chat software. I use XChat IRC, but there are gazillions out there. Then under the FreeNode network add #bitcoin-otc-foyer and #bitcoin-otc channels.
Then follow all of the directions here:
http://wiki.bitcoin-otc.com/wiki/GPG_authenticationThen give a shout out in the forum that you want to buy(or sell) some BTC. Somebody, perhaps several, will contact you. Ask them if you can contact them via encrypted email. If they say yes then you can exchange mailing addresses, bitcoin address, and discuss exchange rate, etc.
Do the trade. After all is received well update the person's OTC rating and you're done. Yeah, pretty brutal but it's the price of anonymity.