I say yes for the 3 gallon, no to TWO, just put in one, it won't give a flyin flip if it's alone, and will probably be more interested in you than if it had a 'friend'. Quite simply, there is no way around proper waste export if you add two, not to mention stress.
I disagree whole heartedly that a 3 gallon for one fish is to small. These dwarfs only get to 1", I happen to have a 1" yellow clown goby in a 1 gallon tank and he is happy as a clam.
Are you sure you only have room for a 3 gallon tank? most people only consider the side to side aspect of an aquarium as far as size goes, however, there is a great deal of variance you can use, Cubes for one, and if you can't go forward, you can always go up. [img]http://www.**********.com/iB_html/non-cgi/emoticons/new/smile.gif[/img] You don't have to do things traditionally either, I know a guy who has a 10 gallon tank (yes, a 10) In his wall, he only displays what we would think of as a side, and has a picture frame around it. It's actually very cool.
I would always of course, reccomend getting the biggest tank you can afford, both size wise and budget wise, and if you can't go bigger, well, you can't go bigger. Many a dream have been truncated by the forces of reality, I don't think this is one of them.