Planche, in this case the one arm planche.  Super tough, if you can do this you would be one of very few in the world!

One armed hand stand perfromed by Assirati.  A great old time strongman who could move a lot of weight but still nimble enough to perform handbalancing strength feats 

Jasper Benincasa performing a solid front lever (in this case holding on with only 2 fingers on each hand!)

Just in case its not hard enough, this guy has added weight to his one armed pull up!

Pistol being performed here is not the best form, as the out stretched leg should be parrallel with the ground, but still impressive considering the extra weight his put on his back.

Body weight master Bruce Lee performing a one armed push up on two fingers - circa mid 60's