From: Dirk Bieber on
Dennis Ferguson wrote:

> Do you know any place where T-Mobile roams on AT&T? I recall thinking
> this was the case when I was a T-Mobile postpaid customer, quite
> a few years ago, but I've not found a place where I've even been
> able to force the phone onto AT&T in recent years.

I found that:

<http://www.t-mobile.com/company/PressReleases_Article.aspx?assetName=Prs_Prs_20040205&title=AT&T%20Wireless%20and%20T-Mobile%20USA%20Sign%20Airport%20Wi-Fi%20Roaming%20Agreement>
<http://www.t-mobile.com/company/PressReleases_Article.aspx?assetName=Prs_Prs_20011015&title=Cingular,%20VoiceStream%20to%20Share%20Wireless%20Networks%20in%20New%20York,%20California%20and%20Nevada>
<http://www.t-mobile.com/company/PressReleases_Article.aspx?assetName=Prs_Prs_20040525&title=T-Mobile%20USA%20to%20End%20Network%20Venture%20with%20Cingular%20and%20Acquire%20California/Nevada%20Network%20and%20Spectrum>
<http://www.t-mobile.com/company/PressReleases_Article.aspx?assetName=Prs_Prs_20030423&title=T-Mobile%20USA%20and%20AT&T%20Wireless%20Sign%20Roaming%20Agreement%20Significantly%20Expanding%20GSM/GPRS%20Footprint%20in%20U.S.>

I don't know the current status. I know you are not referring to WiFi.
Starbucks formerly operated by T-Mobile still offer roaming:
<http://www.starbucks.com/customer/faq_qanda.asp?name=customerwifi>

AT&T and Cingular have had GSM-roaming agreements with T-Mobile, that
with Cingular ended some time ago, but I don't find a press release,
maybe that was reported in investor relations of Deutsche Telekom.

T-Mobile Germany has roaming agreements with Alltel, AT&T Wireless,
Dobson, Nextel, Suncom and T-Mobile US. Yes, I know that Suncom is
part of T-Mobile. ;-)

GPRS should work at AT&T, Suncom and T-Mobile, 3G only at AT&T. #-)

Cheers Dirk