Originally posted by Punki:
No, you can't transfer them to other airlines. (I personally don't know of any airline that allows this, even between acounts for the same airline.)
Off topic but the only two sort-ofs are 1) AA-US where you can pool miles in the accounts to get an award (note: valid for AA or US flights but no partner ones), and 2) BA EC U.S. which allows you to pool family accounts.