Question: things to do with notecards?
Answer: Make a to-do list. Probably the most obvious, but what's great about using index cards for this is that it forces you to be concise. ... 
Take notes. ... 
Create a PDA. ... 
Make context lists. ... 
Keep track of projects. ... 
Create a crazily obsessed organization system. ... 
Create a novel. ... 
Leave a note for someone.