The HTC Sensation 4G is now available for free from T-Mobile, as part of a limited-time offer that the carrier launched this week. The online promotion is set to expire on May 3rd, which also happens to be the day Samsung is slated to announce its Galaxy S III handset. There's no explicit connection between the carrier's promotion and the GS III's launch, but the curious choice of date has already fueled speculation that T-Mobile may be announced as one of Samsung's launch partners later this week, and that the provider may therefore be looking to clear out some of its inventory. Either way, T-Mobile customers now have a few precious days to take advantage of a rather stellar offer, though they may have to wait a bit longer for Android 4.0.