A tool that generates Javascript to encrypt and transform your email address into "code," making it harder for spam harvesters to crawl and add your email to their list.
Like sumif(), countif() for the min() and max() functions
Like sumif(), countif() for the median() functions
Like sumif(), countif() for finding quartiles
A geometric return function
An Excel graphical animated clock
Like Clock2 above, but as a count-down timer
Calculate WACC (Weighted Average Cost of Capital)
Bond calculations
Randomly select Y items out of a list of X (e.g. select winners in a competition)
Shows an interesting use of graphics in Excel - you usually don't think of using the cells as pixels
Creates XML directory files for Cisco 79xx series phones (e.g. 7940)