Smallest Wifi device?

Eye-Fi today announced a 2GB SD memory card that includes wifi. The advertized application is to upload photos from your digital camera to the internet. Presumably it works with other devices such as handhelds also. But
the more interesting aspect is the size of the wifi radio. Arguably it is the smallest form-factor for a 802.11 device (at least the commercially available ones). I can imagine that we can come up with many more uses for such radios e.g. a home network, wifi-enabled cellphones, etc. The spec says the range of the radio is a modest 90ft outdoors and 45ft indoors.