Him bent over with a strap-on up his butt. Hey, he's the one with the P-Spot, not I.

^ Since this is the "Pleasing Her" forum, it's probably safe to say that isn't what bvt meant. ;)

I've found that by lying on my stomach and allowing my partner to enter me from behind, I can relax much more fully and help to control his movements. I believe the Guide just calls this "Rear Entry."

The "Final Furlong" also helps me move along with my partner while keeping my muscles relaxed. It's a nice way for the two of us to stay physically close.

Perhaps not, but that is what he asked and that has always worked for me.

Please read the multiple discussions on the safety aspects of anal on these forums first.

The rectal lining itself doesn't have the sensitive nerve endings that a vagina has - it is the nerve endings in the opening that add meaningful stimulation through the motion and feedback when clenching. Your best bet if you're definitely going to be doing anal is any position that aims you towards her vagina so that you indirectly stimulate it. If her torso is bent in a similar fashion to her on her back holding her knees to her chest, then you can stimulate her posterior fornix more easily. It is more stimulating and safer, however, to use something like a small inflatable dildo in the back that is easy to get in and relatively soft with your penis in her vagina. Since the vagina is pressed between the two, very little movement causes much more stimulation and she gets the feedback from clenching around both. At least one of them should be fairly soft and flexible so that it isn't pinched between two rigid objects.