I have a Edimax ps 1206mfg wireless printer server. In a nut shell it makes a USB printer wireless so anyone on your network can print to it.
I have had it working on Win Xp and Win 7 BUT it was a bit fiddly - thankfully google proved to be my friend.
It comes bare unit with a power supply and drivers if I can find them - although you prob best getting the latest ones fron the net.
£25 Inc with pref for BT