Well I have a Gowearfit that I wear- but it's not a heart rate monitor. I wear it pretty much 24/7 (unless I'm showering) and it tells me how many calories I've burned during the day and how much I've slept, etc. It's called a bodymedia fit now.
I also have a polar F11 heart rate monitor and it's great- I wear it only when I work out and I love it- shows me how many calories I've burned in my workout and how "fit" I am.
I am also thinking of asking people for those wonderful calorie count indexes of all the foods out there. I have one called Food Counts by Corrine Netzer, but I'd like more for comparisons, rather than having to constantly get to a computer and look up calorie counts on the net.