I won a 3G one in a competition on the radio, tried it in Tureky and used the £10 it came with in about 10 minutes. Pleased I did not buy it. Worked fine though and Turkcell do them which will probably be reasonable to use.
Netgear do a 3G wireless router (MBR624GU) which takes a Sim Card. I am thinking of getting a sim card next time we are out and trying out the router, to give me internet access in our apartment.