Here's the best invention since, well, sliced bread and peanut butter: Easy PB&J Jar by Sherwood Forlee:
Peanut Butter: it's the greatest invention ever. The only downside to it, though, is the jar that it comes in. How many times have reached the bottom of the jar only to be frustrated at not being able to get those last few bits? Well, too often for me.
The Easy PB&J Jar is a jar with two lids that allows you to access all of your peanut butter easily without having to resort to breaking open the jar. As you near the end on one side, simply flip the jar over to get the rest. The straight and smooth internal walls also ensure that no peanut butter is ever left behind a nook or cranny like existing jars.
http://www.skforlee.com/independent_work/easy_pb.html