Nylabone make a supposedly "safe" kind of rawhide bone called Roar-hide. They grind the rawhide into rice-sized pellets and then bake it into a bone shape. It's fairly hard, but still edible. It's sold in the aisle alongside the other edible Nylabone brand bone (carrot bones, bacon bones, etc). They're a natural leather, kind of brownish color. They're kind of expensive, I think, for something your dog is going to eat.
We used to give them to our dogs, but haven't in a long time because Oscar can't have stuff like that because of his colitis/IBD, so the other dogs have to go without :( .
The other thing I've read about regular raw-hide is about all the awful chemicals (like formaldehyde) they use when making it.
There's also a kind of hard, chewy bone made by Pedigree called Denta-bone (I think) that we've given the dogs in the past. They seem to like them. They're less expensive than Roar-hide, but don;t last as long. I think I've even seen these for sale at Walmart.
Jen