Tip Calculator for iPhone
Author: Danny Goodman
More Info: Link

A free Web-based application for calculating gratuities for bar and restaurant bills--designed specifically for the iPhone's Safari browser. The application offers two different calculation methods (percent of food/beverage or multiple of tax) and a variety of pre-set percentage or tax-multiple choices. It also calculates the per-person amount when the table splits the check. Once you load the page into the iPhone's Safari browser, you can use the calculator off-line.