My current shoe kit is as follows...

Right shoe - Single edge razor blade, shortened hacksaw blade

Left shoe - R$ 70 ($20 + US) Phone card

I also carry a handcuff key in my left rear jeans pocket.

I have thought of adding additional stuff. My sole (no pun intended) purpose is to give me an edge if I'm ever kidnapped.
I carry other survival items in my wallet, my keyring, Spyderco Endura, etc. The stuff in the shoes is just escape related. Mac