I had a local guy put some horizantal drop outs on my mtb. He originally quoted me $50 ($25 for parts, $25 for labor) but only charged me $25 total out the door. I guess he found some old horizontal drops on an old frame and cut them out.
It isn't the prettiest job and it isn't painted but it is super strong and I am extremely happy.
I can now have my fixed/free flip/flop set up on my mtb!!!