A ruler isn't something that I tend to carry around with me very often, but nevertheless I often wish I had one in my pocket. It would save many arguments in the sandwich shop over their 'foot long' baguettes, and whenever I catch a fish I would no longer have to just gesture with hands to say 'it was this big...' Thankfully, my prayers have been answered with pRuler, an application that turns a Pocket PC into a ruler.
The free software uses the full length of the screen as a virtual measuring tape, giving you the ability to determine the precise dimensions of any object. The settings menu contains a surprisingly large number of options, including a facility for running the ruler in full screen, plus the ability to show measurements in milimetres or inches.
Measuring large items isn't really practical with this application, but with smaller objects, pRuler represents a handy way of sizing things up.