If you look closely, you can figure out which bottles work for capping. You can tell the twist-offs because there's a spiral indentation on the cap winding around the bottle. It's tough to tell, but not impossible. The second thing to look for is a fat ring around the neck (easier shown than described). It should be about a 3/4" wide band around the bottle. If the bottle has that band and doesn't have the threads for a screw top, then it is fine for bottling homebrew.
In the past, there was a thread that discussed all the different beers that come in the right bottles. Steigl is my personal favorite because the bottles are .5 liters and that makes the bottling go faster and also, after a 5 minute soak, their labels slip off easier than a hooker's panties.
It's always a weird feeling when I go into a liquor store to buy un-emptied bottles and the workers keep giving me funny looks wondering why I'm inspecting all the caps and necks on the bottles. Things get even weirder when one of them asks me if I need assistance and I say, "Yes... I'm looking something in non-twist-off bottles... and the bottles have to be brown... do you sell anything like that?"
Yes, that is a real discussion I had with a sales clerk at my local liquor store. No joke!
