After doing a little research on this, I believe that HHonors is the only program that lets you move airline miles in. Some people use Hilton as a "filter" to move airline miles in, where, depending on the airline, you get a 2 for 1 or a 1 for 1 exchange, then they move them back out to a different airline. You can also use Hilton to translate one hotel program into another: for example, I moved Marriott points to UAL then moved UAL miles into Hilton to get a free week in Hawaii.