I thought it would be fun to have a thread on this forum that didn't promote Elist. I found a number of clinical studies that show that show penis stretching devices are effective at adding inches to your dick. Interestingly, there are more studies that show stretching devices increase length with greater results and consistency than there are studies on surgery.
I should point out that one study was funded and run by a maker of a penis extension product and therefore I believe invalid. All others appear to be independent. Look at the top five on this page:
Penile Enlargement, Micropenis and Penis Enlargement | andropenis.com
The only study I have seen on penis surgery was the one circulationg around from the European journal, whose results were much less impressive.