In a 10g your only options are some nano shrimp like sexies, bumblebee, harlequin (obligant starfish eaters), pistol shrimp, pom pom crabs, porcelain crabs, small hermits, gobies, and that's pretty much it from the top of my head...
..and of course species dedicated tanks for small mantis shrimp (neogonodactylids and some gonodactylids), crabs that are perfectly fine in a 10g but threaten other small nano fish/inverts (sally light foots, emeralds, etc..) you get the point there.
This is why you gotta research prior to setting anything up, know what you're getting into.
Every 10gallon I ever setup got teared down withen a month.. they're too difficult and limited to maintain with the small water volume. The last one I had was surprisely beautiful and well established, but crashed after one of my harlequin's failed to finish a rotting starfish and a nitrate spike pretty much blew the tank up with algea nearly unmanagable. This happened only twice in my 125 after moving them and the results were thankfully not as bad or even noticeable for that matter.
If I ever setup another it's just going to be a frag tank or a place to put my n. wennerae to free space in my sump...
but I'm not saying nano tanks aren't rewarding. Check out the nano threads for some inspiration and ideas!
http://www.reefcentral.com/forums/forumdisplay.php?f=75 they can be just as beautiful and rewarding as large setups with the proper equiptment and knowledge.