Kotaku's interesting little rumour regarding the sale of Steam Wallet cards in retail turned out to be true, who knew?!

That's right, effective as of… now, Steam users can opt out of using their credit card information on the online services own convenient software to purchase their digital games and instead add funds to their online accounts by purchasing pre-paid cards from 4400 Gamestop stores across the United States. For those who still feel uneasy about using their card online, this should come as a fairly nice surprise. For most though, who have made do without the cards for oh, I…