Should we build our own day planner?

I've been toying around with the idea of releasing a spinme.com day planner that can accommodate all the stuff we talk about on our calls -- two pages per day with space for booking and technical contacts, built-in goals tracking and to-dos, and other nifty things.

Help me decide whether this is worth investing some time into...

1. Should we do this? 2. If we did this, would you buy one? 3. Should we make small, monthly planners that are wire-bound, or should we make planning pages that work in binders? 4. What features would you want in a musicians' day planner?

What would help you?