This guide will let you share your internet connection by Bluetooth so that you can surf the net on your bed without paying high GPRS/HSDPA rates. Im just summarizing the steps, credits goes to the author of websites at the end of this post.
Nokia n73 (most Symbian phones will do, even Sony Ericsson's)
Feisty i386 (just about any distro will do)
bluetooth dongle supported by Ubuntu (mine is CSR)
wireless connection to AirStation router
Pair up your phone and your computer