GnuBox - share your PC's internet connection to the phone via Bluetooth or USB
GnuBox is a small, free software that allows you to access the internet from your phone using your computer's internet connection - without paying any fees (like GPRS) to your operator, and at speeds up to 400 kbit/sec. You can use Bluetooth or the USB cradle for connecting to the PC.
This has existed for Nokia phones for a while, but not for SonyEricsson P800/P900/P910. Now a new version is available for devices using UIQ 2.0 and up.
Some 3rd party apps (like Opera) were working out-of-the-box with PC suite, but not the bundled applications (Messages, SyncML, etc.) They do work with GnuBox.
(Step-by-step install instructions for: linux PC using USB or Bluetooth with BlueZ drivers, windows PC with USB or Bluetooth over WIDCOMM drivers, WinXP drivers or Fujitsu Plugfree drivers. Should work with other platforms though.)