Thanks all. I ordered a free number, and I see a $3 fee for 911 recovery. I'm hearing from you all that that fee will drop to $1.50 a month (though I'd survive paying $3/mo too).
I'm new to the SIP VOIP world, having previously used only my cable provider's VOIP services (soon to be dropped) and Google Voice. I plan to use Google Voice in the main, if only because I've had a GV number for years, and the New York free number may confuse folks. I'll experiment, though, with the Pay Per Call plan.
I do wonder how providers like Callcentric make any money off me, for $1.50 a month, much of which I imagine goes to regulators. Is there some sweetheart deal with the NY telcos, given that Callcentric is based in NY? Or less cynically, it could be a loss-leader plan, I suppose.