So i've spent some time reading all of the t-mobile 3g network posts that I could find using the search, and some of them were funny so thanks for the LOL's

It seems like tmob uses 1700 for the upload and 2100 for the download frequency's and this is different than the at&t spec.

But some people posted that the chipset if capable of using the network, etc...

So from what I've gathered it was anyone's guess at this point.

Soooo has anyone tried it that has a tmob sim-card solution since they can not be software unlocked yet..??

This may be premature since probably not too many people are on tmob yet due to it still be software locked.

Also if the chipset is capable using using 1700 for uploading would this work automatically or would it be something we could change via a software solution?

I would also be curious to hear if someone tried an officially unlocked or a *sim'd iPhone 3G on T-Mobile USA in one of the 3G rollout cities and what happened.

Has anyone tried this in the growing TMobile 3G footprint?

went to the dealer here in dallas and they said they did not have any 3g sim cards yet.. so yea...

I live in an area which T-Mobile has rolled out the 3G. I tried a new iPhone with different "TurboSIM" like overlays and the only way you can get it working is to turn the 3G off from the settings menu.
I'm not sure if this is because of the sim adapter itself or rather the rumored frequency discrepancies between AT&T's and T-Mobile's network.

are you sure the sim cards are compatible with the 3g network? i went to the t-mobile store and they said they did not have any 3g sim cards yet.

i was told i lived in an area where 3g is also rolled out i have a UNIVERSAL sim.. would be interested in testing this out.. but what do i need then? a new sim card and the 3g plan ordered?

or is it really more complicated and i need some type of firmware upgrade.

I wouldn't be surprised if it doesn't work. From my questions asked of those using other unlocked 3G AT&T phones with T-Mobile, only emergency calls worked while in 3G mode (another item, the 2100 band used for part of T-Mobile's 3G bands isn't compatible with the 2100 [International] band on the iPhone 3G). The main reason is probably no such roaming agreement exists between AT&T & T-Mo for 3G access, and neither has the bands neccessary to work cooperatively.

Just hope the two carriers can work out some sort of roaming agreement, but unless someone makes a 3G-universal phone, I doubt this will happen.