No kitchen should be without one of these. They are inexpensive and easy to find.
This timer provides accuracy to the second; most can be set for well over an hour, and some allow you to program multiple times to run concurrently. Magnetized timers can be mounted on the refrigerator or oven door to free up counter space.
If you're looking for a basic timer with no frills, this is a good choice. The dial is set for minute increments and can time up to one hour. Unlike digital timers, no batteries are required.
Some kitchen tools now offer built-in timers; thermometer timers, for instance, allow you to monitor cooking time as well as the internal temperature of a roast.