It’s not the first time a retailer has jumped the gun on smartphone sales, and it won’t be the last, but it doesn’t always involve an eagerly-awaited model like this: some Walmart stores are apparently selling the HTC Sensation 4G already, in advance of its announced retail debut.

T-Mobile plans to start selling the Sensation 4G at its stores next week, on June 15. It had also announced that some Walmart stores would begin selling the smartphone on June 12, but it looks like they couldn’t even wait that long. Reports from users in an XDA-Developers forum thread tell tales of Walmarts all across the US breaking the embargo and happily selling the Sensation 4G as of now. While not everyone who’s tried has seen success, there are certainly enough Walmarts around to give you decent odds.

Besides the early availability, if you go the Walmart route to score your Sensation 4G, you’ll save about fifty dollars against the price at which T-Mobile will be offering the smartphone. Walmart has the handset for just under $149, while T-Mobile will sell the HTC Android for about $200 after a mail-in rebate.

If you’re on the fence about the Sensation 4G, check out our comparison between it (or, at least, the international version) and another of this summer’s hot smartphones, Samsung’s Galaxy S 2.

Source: XDA-Developers forum, TmoNews