Diamagnetic Levitation

So I want to levitate....(drum roll please)....A REALLY SMALL WORM!!!

First off, I read that the downward pull on the worm will be gr (gravity times density), so then how would I calculate how powerful my magnet would have to be to balance this force?

So thats the mathematical part...

Now, what else can I do with this experiment? I want to test stuff, not just levitate a worm (although levitating a worm is still awesome). Any suggestions?

Thanks
 I am afraid - levitating even small warm seems impossible without use of the strongest magnets in the world. Famous Frog of Nijmegen levitated in a field of 16T magnet. Size of the warm doesn't really matter (unless you want to levitate the elephant) - it is water diamagnetism which causes levitation, and as long as the object is smaller than magnet yoke - it makes no difference if it has 1mm or 1cm. To levitate water (or any living creature, built mostly of water) you must create magnetic field gradient bigger than 1400 T2/m http://en.wikipedia.org/wiki/Magnetic_levitation http://www.ru.nl/hfml/research/levitation/diamagnetic/
 Awww...well what are some easy levitating resources? I know that theres a special type of graphite that works well...any other?

Diamagnetic Levitation

Graphite seems to be easiest one.
But bismuth may work too.
Long time ago I used to demonstrate for students levitation with 1T permanent neodymium magnets and a cube 1cmx1cmx1cm or so of metallic bismuth.