As I said in my second PM to Roy - after reviewing my lenses - those what would be possible for Macro work I have no 55mm filter threads so no practical use to me at the moment - Bids are therefore open to others.
Reverse macros are fun as images have about x25 magnification - its like using a microscope. Usual issues with adequate light, working distance, depth of field as with other macro work.
I read once that the only truly happy photographer is the macrophotographer -perhaps it is the ultra realism and the never before seen detail that is the attraction.
M Plonsky has a brilliant site specializing in reverse lens macros with a heap of how tos:
Plonsky - Macrophotography Article
Note that his reverse normal lens of choice is a
Pentax 50mm F1.4