Firbrosis of the penis is "Peyronie's disease".
Here is an excellent thread from Red:
http://www.mattersofsize.com/forum/...yronie-s-Disease&highlight=Peyronie's+disease
I believe if your issue is just a curve, 'jelqing against the curve' can be a slow but effective process to straightening your penis, according to DLD. I don't recall what thread(s) he said that in, but I do recall reading it.