I was recommended one of these on another forum and I have just received it and used it. Works perfectly on Win7 and pairing with a Gramin speed/cadence sensor.

Delivery was from Hong Kong but I order it on the 14th and it turned up yesterday (although there is a note to say they are currently away – I assume Chinese New Year).

http://www.ebay.co.uk/itm/251657222978?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT