What would be great is a mobile website. i.e. http://www.troublefreepool.mobi that has an interface with links to the calculator, cl/cya charts, and other charts information that is standard for all pool owners.
You could also name it m.troublefreepool.com, since you already have troublefreepool.com registered.
Look something like this:
1. Pool Calculator
2. CL/CYA Chart
3. CL/Shocking Levels
other information that would be helpful remotely.
Nothing fancy, just the facts maam
I have a Palm Centro and I'd think that a site like this would be rather easy to create and maintain. I'm not a web designer so I could be wrong.