What better way to say "I love you" than with a 4G Windows phone? T-Mobile is having a big one-day sale tomorrow in honor of Valentine's Day. To celebrate, they are offering a boat load of 4G phones and tablets for free, including the Nokia Lumia 710 and HTC Radar. As is often the case with love, there are strings attached to the deal. The phones are free after rebate and must be purchased with a new two-year agreement on a qualified plan. Still, this is a bargain for two very solid Windows phones. The sale only runs on Saturday, February 11, so you only have 24 hours to commit.