Definitely a Helicoil: drill out the old threads, tap the hole with the new oversized threads for the Helicoil insert, thread-in the Helicoil with a little Loctite, and then thread in your pedal: you're done.
If you haven't done it yourself and don't have a drill press or the other tools needed to tap the hole, you would want to have a local machine shop do it for you. It takes about 10 minutes and some of the better bike shops can do it. The concern with your average bike shop is, most are accustomed to working with soft alloy cranks or frame materials, etc..., not the harder steel that may have been used to make your cranks.
Last edited by TandemGeek; 12-29-07 at 06:05 AM.