Take a look at our Smartphone page and you'll see several GSM PDA phones. UK pricing and carrier subsidies are different here in the US than the UK, so I'm not sure of pricing in GBP, but there is the XDA II, the XDA III (recently introduced), and the soon to be released Treo 650 which is Palm OS. The Treos don't have WiFi though, and the currently available Treo 600 lacks Bluetooth while the 650 has Bluetooth. In addition there's the iPAQ 6315 (sold as the 6340 in Europe I believe) which is a nice Pocket PC phone with both Bluetooth and WiFi.