Sorry I didn't specify, yeah, Tmob allows you to use VoIP on their highest pckage- which costs a mere 17 quid per month on top of the monthly plan, an amount I'm not prepared to pay...
@Morba, I can't see why this would be like chipping consoles, it's got nothing to do with it. Networks cripple phones to suit themselves, why should it remotely be taboo?
Lessee...
3G
Standard f/w
Orange- Can't use VoIP
Vodafone- Can't use VoIP
Tmob- Can use VoIP on highest data plan
O2- Can use VoIP if you are prepared to pay out the nose for a stupidly small amount of data
Debrand & upgrade the f/w
Orange- Can (?)
Vodafone- Can (?)
Tmob- can't because they block the actual ports (?)
O2- Can
Wifi (this is what i'm confused about)
Standard f/w
Orange- Can't use
Vodafone- Can't use
Tmob- can or can't?
O2- Can
Debrand and upgrade the f/w
Orange- Can
Vodafone- Can
Tmobile- Can
O2- Can
If anything looks wrong there i'd appreciate if it could be corrected, many thanks

I'd just like to use my N95 like it was designed to be used, and the British networks are making that a little bit complicated...