I have a male cat named gizmo. I can't afford to keep him.

He isn't fixed, and he's never had any shots. What do I do with him? Humane Society and Cat shelters say they're full, and I've tried all I can think of. Does anybody have any advice on what I should do in this situation?

He's a good cat and I don't want to do this
But I don't know what other choice I have :(

I saw some cats that had previous owners at Pet Smart you might try the pet stores.
Ask around too.