I thought you had bought one. The pictures look good. For Canon macro there is three choices. The ef-s 60mm...nice and sharp but a little short on focal length and can only be used on crop cameras like the 40D. The Canon 100mm f2.8 macro, which has length, fast focus, and speed. A good choice and the one I prefer. The last one would be the Sigma 150mm. I don't usually go outside of the name brand, but this is one lens to do it. It is f2.8 and has length at 150mm. It is sharp and comes with a tripod collar, unlike the Canon 100mm. I think in the end I would still go with the Canon, but it's close. Let me know what glass you end up getting.
Shawn