It's amazing what you can pack on your wrist these days. The Casio Pathfinder watches are perfect examples. We tried out the 1500-1V, one of a dizzying array of Pathfinders available, and it's across-the-board impressive.
The 1500-1V is a beefy, medium-large watch with a 51mm bezel diameter and 14mm case thickness, but at 2.6oz it's not too heavy on the wrist. It's an ABC watch (altimeter/barometer/compass) designed to be your backcountry buddy, water-resistant to 200m (SCUBA-friendly!), with every possible time-keeping function you could want including a 1/100 second stopwatch, 5 daily alarms, countdown and yacht timers. Don't know what a yacht timer is? OK, neither did we; it's just a countdown timer with beeps, which is actually kind of handy.
For good measure there's a useful backlight, thermometer, tide graph, moon age and phase graph. Oh, and it's solar-powered, and the multi-band radio receives time calibration signals 6 times a day in compatible locations to syncronize with the atomic clock. If you're a total feature-whore this is definitely the watch for you. Measurements are accurate to the degree you would expect on a watch, i.e. not professional grade but plenty good enough for backcountry use.
Our tester came with two bands, a normal style one with a buckle and a thinner, larger one with velcro, designed to be worn over winter clothing. If you don't have massive arms you can actually use the winter strap over your upper arm for running, swimming, etc. Very useful. If you're looking for the total package short of a GPS unit, definitely check out the Pathfinder series.