I don't have one but I know someone that does and they love theirs;
Oregon Scientific (SE138 I think is the model my friend has) strapless heart monitor - pulse watch. It's around $80.
Just in case anyone was wondering...
Strapless heart rate monitoring is an accurate method of measuring heart rate without the need to use a chest strap, but don't buy a cheap pulse detecting (motion / optical sensing) watch as they're not very reliable. Proper units require you to put 2 fingers on the sensors for between 4 to 12 seconds to get a reading, they provide heart rate ON DEMAND only, and do not give a constant heart rate reading, but they are ECG accurate.
For general exercise in the gym etc. chest strap type HRMs are recommended, as having to hold your fingers to your opposite wrist can be cumbersome whilst (for instance) running.
Sportline Duo 1010 Dual Use Heart Rate Monitor with or without the chest strap