I moved my cycling computer to a Polar CS200 system. Aside from the basic measures, distance, speed, elapsed time, the unit also tracks cadence, heart rate, laps, and has an alert mechanism to keep certain parameters within range. For example, a heart rate alert that sounds when your heart rate exceeds 85% of maximum.
The unit can also transfer all of the tracked data to a PC for upload to a journal-based website. In a few minutes, my ride data can be captured and stored for trend analysis and managing training goals.
Here is a picture of the unit. And below that is a picture of the unit that I used to have many years ago.