Does anyone know anything about this guy?

[ignignokt.livejournal.com]

He's been visiting us (and at least one other neighbor that we know of) for a couple of months around Union Square. He's very skinny, always ravenous, and occasionally has some scratches or a rash, so we assumed he's a stray. He's also unneutered, so maybe he's never had an owner.

We were thinking of taking him to a vet to get checked out. Does anyone have any idea whether or not he's had an owner or have any other useful information about him?