Not sure if this qualifies as a butt plug, but I found a Pyrex wand that I bought years ago - hoping my wife and I could get some " double play" action going. Never worked out so it got stowed away and forgotten.
I've been looking for a long wear plug that create good prostate stimulation. When I found this toy, I popped it in for some fun. What I discovered was that it is very comfortable to sit on or walk with. With very little rocking or walking it give an incredible prostate massage.
So far, I've worn it about four hours through various activities and in and out of the house and absolutely love the sensations.
Here's a picture of it. http://www.zity.biz/gallery/image/108659