I've been doing something similar to this for quite some time.

I made a Google-docs form containing boolean-answer questions regarding whether I did any of the things I aimed to do regularly (running, writing code, good interaction with people, etc), and wrote a script to remind myself to do it every night via email.

Answering "No" to a question put a nasty red mark on the generated spreadsheet, which led to a huge motivator as to avoid the nasty red marks on the otherwise clean spreadsheet. Now, after doing this for almost exactly a year, I can claim that this system works quite well for me.

I'm going to make this into a full-fledged app inspired by the "Calendar about nothing".