Since starting to incorporate some of Scott Sonnon's material into my training I've been toying with the idea of doing a 4x7 protocol with just body-weight exercises. I am likely to do this in November after the IKFF cert. My thoughts on body-weight training reminded me of something my Systema (Russian martial art) teacher said during one of the classes. I'm loosely paraphrasing what he said but it amounted to the following: Everybody seems to believe that getting fit requires money, gym equipment etc. All you need to do is lie down on the ground flat on your back. From that position get up to a full standing position in the most efficient way possible. Do that for 10-20 minutes at a time and you will never need a gym again.
Vadim (my teacher) actually made us do this for 5 minutes during one of our classes and I can assure you it is not fun. Such is the weird and wonderful things us humans do with our bodies.