T-Mobile in the UK has launched an HSDPA-enabled data card in the UK, but at the same time has banned the use of VoIP across the service. The fine print on the new Web'n'Walk Professional service explicitly prohibits both Instant Messaging and Internet Telephony services across the network.

"It's a commercial decision that we took," admitted Langton. "We charge two and a half times less than our competition. We're aiming at the business network. We spoke to our customers and it's not key to them," he told ZDNet UK last week.

However, Langton didn't rule out the possibility of an eventual solution that avoids losing out to third-party clients. "If we find customers are coming to us and saying that they want messaging, well, T-Mobile is not about to tell them they'll never be allowed to message," he said, adding, "It might be a T-Mobile client."

Analyst Tony Lock at Bloor Research thinks that this may be the precursor to a T-Mobile VoIP client.