External sex related sites
A long time ago I came across this website about the G-Spot and the prostate. Non-profit, nothing to sell but really awful layout and it hasn't been updated in quite some time.
Be that as it may, the site does have a lot of details about both the female G-Spot and it's male counterpart, the prostate. It provides some valuable information on such issues as coital alignment techniques and so on. I've known the guy who set up those pages when I was living in Germany, so there is also a German version of this available.
English pages here:
G-Spot
German pages here:
G-Punkt
I will be extending this post as I go along, for now... I must be off to do some shopping and other errands.
Again, if you have anthing that is non-commercial and does not compete with this forum or their paysite, feel free to add.