This is based on reading of the freeswitch website and some experimentation
First, get an up-to-date Linux-based VM. My choice was the "Ubuntu 9.04 Desktop with VMware Tools" authored by Chrysaor (VMWare Appliances page here, author's page here). Obviously you'll need to get VMWare Player as well if you don't already have it (here).
Now the Vodafone SIM is working I can play with the Nokia N71 that came with it. So far it seems to be an amazingly good phone.
Of course it makes phone calls & sends texts, but it also has good usable PDA functions (email -- POP/IMAP, calendar etc) all of which syncs via usb or bluetooth with outlook. And an easy to use WiFi interface to not only webbrowse (as an alternative to it's GSM/UMTS interfaces) but also to use built in apps like the VoIP/SIP client, Internet radio, email client, etc,...
And unlike the Windows Smartphones the battery seems to last a long time too.
