T-Mobile has launched a Seattle Speed Challenge in which it is asking iPhone users to bring in their phone into one of 10 of the company's participating stores to take part in a speed challenge. Between April 29, 2011 and May 1, 2011, if your Apple iPhone can beat the Samsung Galaxy S 4G in two out of three download speed tests, T-Mobile will give you $1,000.

T-Mobile says it has been making significant improvements to its network, and it is now confident that the Galaxy S 4G running on T-Mobile's 4G network can beat the iPhone, which runs on Verizon's and AT&T's 3G networks. Here are the 10 addresses for the locations of the speed challenge in Seattle: 1527 6th Avenue, 13242 Aurora Avenue, 1216 N. 45th Street, 8355 15th Avenue NW, 12513 Lake City Way NE, 401 NE Northgate Way, 1012 Bellevue Square, 3720 128th Avenue SE, 20804 Bothell Everett Hwy, and 7521 166th Avenue NE.

Here are the official Speed Challenge Requirements:

  1. Speed challenge offered 4/29/2011 through 5/1/2011; subject to change. First come, first served. Participating locations only.
  2. Limit one speed challenge per person.
  3. Participants must be 18 years of age or older and a legal resident of the 50 U.S. states or D.C.; iPhone models used on the AT&T or Verizon Wireless network (and not over Wi-Fi) only.
  4. Participants must agree to complete a T-Mobile survey / information form.
  5. Participants must download a free speed test Application specified by T-Mobile; standard data charges apply.
  6. Speed challenge consists of three tests of the Galaxy S 4G versus the iPhone based solely on download speeds as measured by the Application; participants will be eligible to receive $1,000 if their iPhones are faster in two out of the three tests.
  7. Successful participants must provide contact information; affidavit of eligibility and a liability release may be required.
  8. $1,000 provided in form of check; allow 6-8 weeks for delivery. All applicable taxes are the sole responsibility of the recipient. If check is returned as non-deliverable or participant is not eligible, $1,000 will be forfeited and T-Mobile will have no further obligation.

T-Mobile specifically chose Seattle because its HSPA+ 4G network is not available everywhere. The Galaxy S 4G is designed with HSPA+4G technology, but it's not the only 4G phone T-Mobile offers; there's also the T-Mobile myTouch 4G and the T-Mobile G2, both manufactured by HTC.

T-Mobile has always fought hard against AT&T and Verizon with different types of marketing campaigns. This one comes at an interesting time though. Last month, AT&T announced that AT&T announced that it has entered into a definitive agreement to acquire T-Mobile USA from Deutsche Telekom in a cash-and-stock transaction currently valued at approximately $39 billion.