Ok, serious post:
Truly feral cats are wild, and not easily befriended. Your kitty was likely abandoned. If you get the kitty checked out at a local vet, and bring him/her inside..and the kitty STAYS inside, germs will not be a problem. Cats are a wonderful presence in the home. Consider it.
With respect to humane society-type organizations, the kitty will likely have ~72 hours or so to be adopted after it is deemed adoptable before it is put down. The shelters are simply too overcrowded.
You'd probably have pretty good success listing the kitty on Craig's list, as free to a good home.
Just my $.02 worth.