I have taken a few of these. For one, I caught a fly and stuck him in the freezer for a few minutes. You can get off a couple of shots before they come out of it. However, it's so much easier to get a capture of a dead subject because, with this setup, your working distance is only an inch or so. A true macro lens will get you decent results without having to look around for dead bugs
. However, you can't get this much close up detail with a macro lens.
It's actually a heckuva lot cheaper than you think. You already have the two lenses so all you'll need is a reverse coupler and 2 rings. All can be bought on Ebay for around 25-30 bucks total. I showed Nimrod how to do it here: http://www.findmall.com/read.php?36,281252,282463#msg-282463 Mind you, this is when I first started trying this technique so the shots aren't all that great. You just need to know the ring sizes (filter size) for your 70-200 and the kit lens. Then look for a "coupler" for the 70-200 and a step up ring for the kit lens to go into the coupler. Here is a shot of a dandelion stamen after I got used to doing this.
[attachment 29651 stamen.jpg]
As you can see, shallow DOF is crazy with this setup.
The first site I would recommend would be www.dpchallenge.com . It is a photography challenge website but there are many educated photographers who are more than willing to help in the forums. I've learned a great deal there. I used to go to www.photosig.com, which is a decent place to get critiques on your images, but the admins over there are pretty much a-holes anymore and I won't support a place that is in to such negativity. www.pbase.com is also a decent place for help if you ask for it.
Good luck to you evetS.