My quick look at available, experienced OTs (perhaps some of them have been picked up):

Wayne Gandy (Atl), Fred Miller (Chi), Tom Ashworth (Seattle/NE), Stockar McDougle (Jacksonville), Nat Dorsey (Cleveland), Kyle Turley (KC/StL), Todd Steussie.  They are all old timers -- perhaps the immediate short term plug we need.  I think NE actually picked up 2 veteran OTs in the past few weeks.

I doubt that waiver wires will present much other FAs at this point in the preseason, and we need bodies right now, I guess.