Lately, several "hacks" and enhancements have been released for enhancing the Windows Mobile platform. Windows Mobile devices used as modems are pretty common. Currently, as of version 6 of Windows Mobile, the official ways you can use a WM-based phone are pretty limited. These new hacks allow for using the old, widely supported Bluetooth DUN access (as opposed to the less supported and more complicated-to-use, BT PAN-based, new approach) and Wi-Fi.

I've just posted brand new, updated versions of both tutorials explaining how you can use dial-up over both BT DUN and Wi-Fi. Now – in addition to other niceties; for example, BT DUN is, now, much easier to be installed (you, basically, only need to install a single CAB file. NO registry importing, file copying etc. needed) – , you can use both (Wi-Fi and BT DUN) based access to your Windows Mobile device working as a modem.