Could be a Don sphynx / Siamese mix? Which is the foundation for the Peterbald or S:t Petersburg sphynx...Why anyone would throw out on the street I do not know.
http://www.peterbald.ro/gb-history.htm
http://www.peterbald.se/florence.mp3
Horny cat hasn't run out of horny..
and for everyone to get the little reference http://www.peterbald.se/happycat.jpg