It looks like the studio is selling props and other stuff used in Cloverfield on ebay! So here is your chance to get authentic merchandise and props from the movie. You can check out all of the stuff using the link below.
As Hodge pointed out, there are a few auctions for supposed images of the monster on mousepads, the images are drawings from a fan based on what he said he saw in the movie. Personally, I saw the movie and dont think that looks like the monster that I saw on screen.
Featured Cloverfield Prop For Sale