Well, what a pleasant surprise it was for me to discover hidden treasure in the Calculator app in the Instinct. I was missing the unit converters and also a special tip calculation app I had in my previous Treo 700p. The Instinct has that already built in. Nice!
When you go to Calculator, just tap the upside triangle icon on the upper left-hand side of the screen. You're then given 3 choices:
(2) Tip Calculator
(3) Unit Converter
If you choose (3), there'll be more choices under the upside triangle icon on the upper right-hand side again: Distance, Temperature, Speed, Volume, Weight, Area.
I like the 3 options for calculator, however, for the basic calculator it lacks a percentage key. If I try to convert to a decimal, it won't provide enough decimapl places. Unable to use calculator when calculating tip at 4.712%.