hacking iphone to do wifi calls?

I know there's a million places making these claims, but I'm curious if there's anyone on this forum that knows the technology enough to know if this is possible:

I have t-mobile and I use the "hot spot at home" service which lets me use my t-mobile phone to search for a wifi spot and if it's not locked, it
'll jump onto that service and I can make free calls. It's the UMA technology. I'm curious if it'd be possible to hack an iphone and put in my t-mobile sim card and have it do the same thing?

This is all because I want to be able to read my google calendar on my phone and I don't have outlook to sync my phone to.

Any thoughts?

:guinness: :roll: :roll:

Dump the iPhone and wait for Android.

well I don't have me no iphone yet, and I'm going to go google Android...

I use a 3G Blackberry device, primarily for the superior push e-mail capabilities. Several of my friends have an iPhone, and I think they are great devices. However, I still think the Blackberry is the right handheld device for me.