Already back in 2006 I have speculated about Wifi/3G devices becoming gateways to the Internet for Wifi only devices (notebooks, etc.) by acting as Wifi access points. Looks like we are very close to such a solution now with JoikuSpot. JoikuSpot is a piece of software for Nokia S60 phones which is able to relay HTTP and HTTPS web page requests from notebooks and other Wifi devices to the Internet via a 3G connection.
According to the description, the software sets the phone’s Wifi interface into unencrypted ad-hoc mode (not in Access Point mode) which means that everybody in range can use the gateway. This is a bit of an issue from a security and usage control point of view. Another current downside is the limit to HTTP and HTTPS which limits the use of the gateway to web surfing. eMail and other Internet applications. An interesting step, let’s hope they continue to work on the feature set in the future.
Something similar has been achieved with Windows Mobile based phones, as mentioned on xda-developers.com
you better have an unlimited data plan if you download this software…