Okay, I thought I came up with some good challenges and a fun freebie to go with them. I seem to be getting some followers, but not a lot of people trying them.
What kinds of things are you all interested in? I can find all sorts of things, many of them are math-y (statistics and things like that), or string management and still others require you be willing to handle things like differential equations.
If you mention what you might like I can either find some or make some up.
@Absinthe I'm an algorithms guy myself, all about making hard tasks efficient. But not so sure that would attract others as much. I will reshare any challenges you have though and try to do them myself.