Sand, rock, shrooms, polyps, low light softies and inverts (and still might want to invest in a small PC setup), and maybee a shrimp or hermit. I would not all any fish to something that small.
I have a 4 gal 'Love Hut' for my mantis shrimp. It is great. I am thinking of getting a 27w LOA from home depot, and getting a bigger chunk of LR for him to live in. Right now, all I have in there is a few pieces of rubble.