There’s not a lot different between Polar’s H9 and H10. In this article I explain what actually is.
An iteration of the OH1, Polar addressed some usability issues and increased the range.
The Jabra Wireless Pulse combines a heart rate monitor with a headset. Even less to take along on your run.
The TomTom MultiSport Cardio has a nifty feature that it measures your heart rate on your wrist. It uses green LED lights and a sensor to measure the blood flow and by that determine your heart rate.