If you have a modern digital camera or point and shoot, the most obvious thing to do is send it back to the manufacturer. So if you have a Canon EOS and live in the US, just send it back to Canon USA. You can usually find repair facility addresses and phone numbers by surfing the manufacturers' Web sites. If you live in a strange Third World country, you can still FEDEX in a camera body with a credit card number and get your camera fixed by the US importer.
If you have an old 35mm camera with sentimental value and are prepared to spend $200 to make it work again, you might think that sending it back to Nikon or Pentax or whoever would work. However, invariably the manufacturers don't want to deal with models that are more than 20 years old and will tell you
that "parts aren't available." You need an independent shop that is willing to cannibalize junk bodies, machine parts from scratch, and otherwise exercise creativity. A traditional favorite is Professional Camera Repair in New York City: (212) 382-0550.
If you have a Hasselblad, consider sending it to Gil Ghitelman (referenced in our where to buy a camera article ). He employs his own Hasselblad repair guy.
New England's only camera repair legend is Steve Grimes, 401-762-0857, www.skgrimes.com. He solves all kinds of strange large format problems with custom machining. He also does bread-and-butter large format shutter repairs, lens mounting, etc.
We're not experts on camera repair shops in every state. You'll probably get the best advice from our Neighbor to Neighbor service or the user-contributed comments (below). If all else fails, you may need to buy a new camera from one of the photo.net recommended retailers.