So, I thought I'd do a quick demo of how Ireverse, since it seems that people may be slightly confused.
Firstly: I use an 18-70, but I very rarely go below 35mm as it's just too difficult to control the at that length.
Here's a test shot of a 10c piece at 50mm using my new setup:
As you can see, the covers almost the entire image, which is useful.
Quick tips: Focusing using rings is out with this setup - to focus, you have to practice rocking your body back and forth slightly, and you have to be pretty close to the subject (within about 10cm at 50mm)
I use the body and flash for shooting obviously, but this shows that I have used a rear cap to hold the lever open by cutting a big hole in the back of the cap.
The mount to the body involves a reversing ring (purchasable from ebay) and a hollowed out body cap, mounted together with (in this case) medical tape, but I'd prefer to use electrical tape as it looks much better. a black cap would be good as well.
Anyway, now that you can see how I do it, go out and have fun!
Gotta love ghetto
PS: I thought I'd repost this here as in the Macro section this guide received approximately NO views.