I agree with Heather... It looks like you may have the DA 50-200? If so the raynox 150 or 250 will clip on it and give you some pretty nice macro shots. They are only about 40 bucks, so If you really enjoy the macro shooting after using them, spend some real dough and get a dedicated macro later.
There are a couple of folks on this and the other forum that are doing some amazing macro work with this combo. Do a search on both forums for Raynox 250 and you should get some results.
Here are a couple of shots I took with my DA 50-200 and the raynox 250.... the raynox 150 will give less magnification but with more DOF