very small aquarium

Question
I recently bought a small (approximately 3 gallon) aquarium for my son.  This apparently was a mistake, since I can only put 3 fish in it, and most hardy fish are supposed to be in groups of 6!  What (if any) fish can I put in there?  I know a betta would work, but anything else?  I haven't put anything in it yet except dark gravel and a few plastic plants.  Well, and water.  It's been set up for about 2 months with no fish while I agonize over what to do.

Answer
You could get some Endler's Livebearers which are very small.   You could have 4-6 in a 3g.  They do have live fry, so stick to males only.  You could skip the fish and go for shrimp (but keep in mine they are sensitive to poor water conditions and are a bit more work).  A Betta is a great choice for a first fish, I have one in a 2.5g on my desk.  I think you could put some white cloud minnows in, but you could only have a few.  Certainly you have more choices with a bigger tank, but small tanks can be great.  Add some hardy plants like Java Fern and Java Moss and you have a great little environment and not a lot of work.