Ideally, here's what it would do.
Like tweeting, you send a SMS to a number. You are creating a personal log. It records your message, the date (automatically), and a tag. Here's a few sample messages to show how I would use it:
Finished Veronica, Mary Gaitskill; @books, @log
Dreamt dad sitting on tire swing, I pushed him off; @ dreams, @log
idea for new play: old high school bullly earns second degree learning from teacher he once bullied as kid; @ideas
short story read: xxxx by xxxx in New Yorker june 2010 issue; @short stories, @log
finished draft of xxx; @writings, @log
Etc. And all it would have to do is create a database that you can access on the web that you can view (and print) in calendar or spreadsheet form. That's it
A secondary option: use "z-1" to mean you did it yesterday, "z-2" two days ago, etc.
I WOULD LOVE THIS APP.
For 2 reasons: no where to record ideas on the go
Nowhere to record personal history on go and it always seems like I do nothing. I've always found that looking at a log of what I have accomplished (even if the accomplishements are small) make me feel so much BETTER.
I would call it TAGLOG (like tagalog without the A) or TAP A Z (and incorporate the "z" idea, above.)