There's one guy who is constantly begging on the New Jersey Transit trains in Penn Station NYC, he claims he just needs a few bucks for a ticket to get home (common scam actually, this guy is just more regular than most). Of course he's full of shit, as another guy on my car proved by offering him a ticket to where he wanted to go, and when he refused it, lit into him about how he was a pathetic loser who was making his race look bad.
Then there's the "Why Lie, I Need a Beer" guy also in Penn Station NYC. Though I think he's actually not homeless at all but a cop of some sort, he seems a bit too healthy.
And the bunches who fake some sort of deformity. They seem to have shifts worked out; maybe there's an organization who controls it. Anyway, they get in their contorted positions and hold out a cup or a sign or whatever. Then when their shift is up, they straighten up, pick up their stuff, and go.