Have you had your cake yet? If you haven't then you haven't played the innovative and award winning puzzle-action game Portal from Valve. This weekend may be your time to find out what all the fuss is about as Portal is the subject of the regular weekend sale on Valve's Steam service.

Portal is priced for this weekend only for just $9.99, a 50 percent cut for its normal price of $19.99. With that you get a game that, while extremely short, is still challenging and entertaining (and not without more than a little humor). Valve is reportedly working on a sequel to Portal but it may be a while before that's even officially announced.