Some have made their own. I've been lusting after one for a long time but haven't been able to justify buying one yet. I'm the only home mechanic I know who owns the dropout straightening tools, which might indicate I've gone a bit too far.

Straightening the derailleur hanger is cheap enough if you bring in the bike with no rear derailleur attached and hand it to the mechanic. He can do it right quickly and cheaply that way. It may be $5 to $15 each time.

In the meantime, I've been eyeballing it and bending it when needed at home.