While turning down the full body scan has always resulted in a pat-down, there's a newer "enhanced" screening procedure that's being tested at some airports if you opt out, like at Boston's Logan airport. Here's what's it like described on Daily Kos:
Two (female) TSA officers stepped over to me, and gave me the new procedure, which included touching my face and hair, and in between and directly under my breasts. Much like a medical appointment, they explained the motions they would make before actually touching me, and both women were professional and polite about the screening - even apologetic about it - but I couldn't help but think this was overly invasive overkill.
And on another blog:
Immediately, the screeners we very rude to me and ordered me to sit down, which I did. I waited with no communication and no acknowledgement that my wallet and carry-ons had long since come through their screening, and were waiting on the other side for anyone to pick up.
Finally a team came over, had me go through the metal detector, collect my things and go to a separate area. These screeners were very pleasant, if also thorough–they took every single item in every pocket of every bag and swabbed each separately, and scanned for explosives. They patted me down and asked a lot of questions.
The Transportation Security Administration confirms to Christopher Elliott that it "is in the process of implementing an enhanced pat-down at security checkpoints as one of our many layers of security", which is being tested in Boston and Las Vegas.
They're more coy about how and when the new, gropier screening technique will be implemented across the US, but the gist of Elliott's conversation with the TSA is that it's either going to roll out out nationwide on October 31, or it's going to be phased in gradually. (I would guess in time for holiday travel.) So get ready to spread 'em. Or, um, spread 'em. [Elliott.org via BoingBoing]