Gnome NetworkManager

Gnome Network Manager  is an application to manage a variety of Internet connection types, e.g. Ethernet, WiFi, dialup modems and now also Mobile Broadband devices (3G modems). There has been support for devices using option.ko and usbserial interfaces since version 0.6.0 I believe. The latest version (0.7.0) even supports the newest hso.ko devices and I have written a How-To to explain what you need to do.