T-Mobile has registered over 300,000 registrations for the Galaxy S5. Previously, we had reported that the US carrier had breached the 100,000 registration mark, and is now on its way to half a million (by the end of March, at this rate). The Samsung Galaxy S5 is on schedule to launch in 150 countries across the globe on April 11th. Bear in mind, one registration does not equal one sale. It will be interesting to see just how many people who have registered for the Galaxy S5 actually end up buying one.