They are fine with peaceful community types (tetras, peaceful barbs, cories, etc) and I keep mine in a heavily planted community tank with angels and a rainbow cichlid in there too.
I wouldn't keep them with anything aggressive, like any medium/large cichlids (or certain aggressive smaller ones like convicts for that matter) that might be tempted to eat them or bully them. But as long as they've got plenty of places to hide, they make great community inhabitants
I agree with Lisa A nice peaceful tank of at least 20 US gallons + with some bogwood for resting (furniture) or Amazon swords (though they do like munching them too).