On various threads here, I've seen some pretty cool ideas.
Some people use an El Cheapo nylon holster (Uncle Mike's, BlackHawk, Some No-Name, etc.) and bolt it to the side or underside of the frame. Some find powerful magnets like those in an old speaker destined for the garbage, and mount that to the side of the bed. The gun just sticks to it and will stay there until (God forbid) the unthinkable occurs.
I guess the point is that while you can find pre-made products all over the web, sometimes the best (and cheapest) route is the DIY way.
Hope this helps!