THIS, LISTEN TO THIS MAN!!I agree with niko. :yh:
Pick up a Raynox for about $50 just to see what you are able to do, OH YEA, you will deffinatly need to get a tripod also.
Here is a thread (i'm a Pentax guy but it will give you an idea of what to expect) that shows what the Raynox can do.
The Raynox Macro club - PentaxForums.com
Tripod is a MUST for macro shots!
Also, if you can also get hold of a remote control, I suggest you consider getting one.