Update:
On the Ancestry Facebook page, somebody posted this information about using your raw data from Ancestry to compare outside their site:
On your DNA page top right is an option to download your raw data. You need to select and then they will email a link with the address on file. Once you have that, you can go to GEDmatch and follow the instructions to upload. Unfortunately, they are not accepting new data until on or about August 15th. FamilyTreeDNA also has the transfer function. Go to their page and scroll down to almost the bottom. FTDNA charges, GEDmatch is free.
Click this link to get to my DNA post.
The Family Kalamazoo 