Originally the battery grips for the 550D and T2i were very hard to come by. There were no aftermarket ones available. There were of course aftermarket batteries, which I was able to purchase and they work great, but I had to special order an OEM canon grip from Calumet in San Diego. I just got a comment on my last post about the aftermarket batteries for the T2i / 550D, stating that the Aftermarket grips are now available for as low as $69.00 dollars and they come with x2 batteries + Free Shipping. You can find a list of these grips following this link.
Below are some images i've grabbed from an eBay seller, and they look pretty spot on to the real thing.
Click here to buy Aftermarket Battery Grips + Batteries from eBay for the Canon EOS 550D T2i
If anyone has already received these items, holla back, comment on this post, or share it through the Share widget below.