I'm looking to make some changes to my cell phone service in the next few months, so I just called T-Mobile to find out exactly what changes would require an extension of my contract. Specifically, I was wondering whether adding or removing a Data Plan would force an extension - I was pretty sure it wouldn't, but I wanted to confirm. According to the CSR, not only do data service changes not require contract extensions, but T-Mobile no longer requires an extension for plan changes either - minute changes and the like can be done mid-contract without any penalty. He said that basically the only change that requires an extension now is a subsidized phone upgrade. I was really surprised by this, so I'm looking for independent confirmation but I can't seem to find anything on the web. Has anybody with T-Mobile changed their plan lately? Any insiders care to comment?