I feel strange discomfort understanding that the key to my "crypto wealth" is just a set of 256 random bits. Anybody can just write a random number and suddenly unlock somebody's funds. Mathematics tells us that probability is very low and we believe it, because it is correct. But we miss the important fact that there is another factor - the implementation of random key generation. The problem is that part is not easy to verify. It may appear many years later that some popular wallet apps had the generation issues which can be exploited by some power hardware.
So I decided for myself to not believe to what I can not to verify and generate the keys with a coin. It is boring to write each bit on paper, so I made a little python script that accepts keyboard input of '0' and '1' after each coin flip and finally compiles the bits to different keys representations.
It can be downloaded here:
https://gist.github.com/webzak/31c5bd933f742cdc51ae
The Vitalik's https://github.com/vbuterin/pybitcointools lib is required. (pip install pybitcointools)