I am so grateful for the break in the weather. I use the heart rate monitor that came with my Garmin Forerunner 305 (I think). It isn't without it's issues. The read out is super dinky. With my granny eye onset, it's pretty hard to read. However the alert system is great - and I can still hear (most of the time). The alert system doesn't let you program in exact numbers - only zones based on your Max HR. Sometimes I have to tweak my Max HR to get the zones to be what I want.
Hubz has a 405 Garmin, and he can get his to just display HR if he wants. It's big enough to see. When I get back home, I'm going to try the cheap Timex one a girlfriend gave me. I know it gives a bigger readout.