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.) Anyway, if for instance you want a USA domestic coach ticket on AA you must have 25,000 miles in you AS account and would book through the AS partner desk.

If you have less than 25,000, the only things I know you can do with them are upgrade an AS flight, get a 50% discount on an AS ticket, take an Amtrak train, fly on a small regional plane within Alaska, get more AS miles or donate the ones you have now.

QuietLion sometimes knows obscure little things about airlines programs that I don't so he may have something to add. TravelWeary knows everything about AS that I don't, but she thinks it is good for me to learn from my mistakes, so she waits until after I do it the hard way to tell me the easy way.