Maybe take it to the HUMANE society, where people look for thier pets at? What if its chipped?
And as far as ME doing something.. I have done my fair share of rescuing animals. You are taking this on yourself.
You posted it up, with CLEAR signs that it is someones cat, and yet want to give it away. If the cat came to you, dingy, hurt, no signs of ownership, I would understand. But the pics show a reletivley clean cat, WITH some sort of collar, who is FRIENDLY.
Not everyone is in the Techno world. Some people actually still leave the house to look for thier pets.. I would notify the Humane societ and other cat sanctuaries in the area.
What if they moved into your complex, he got out and they havent seen him since, because he's confused?