T-Mobile today announced that its variant of the Samsung Galaxy S5 will be available for preorder beginning March 24. T-Mobile is offering the device for $0 down, followed by 24 monthly payments of $27.50 (~$660 total over two years). Those who preorder before March 31 will be eligible for $120 off the Samsung Galaxy Tab 3. T-Mobile indicated that more than 500,000 people have preregistered for information about the GS5, but people who actually preorder before March 31 will be the first to receive it once it goes on sale. T-Mobile didn't say when the device might ship, not did it announce plans to carry the Gear 2 or Gear Fit wearable devices.