Does anyone have a good idea of about how many calories you can burn in an hour on the elliptical? I know the machines tend to overestimate by a lot...I don't have a pulse rate monitor.

If the machine says 750 calories in 60 minutes of intervals, do you guys think I can safely count 500 calories burned?

There are websites (such as about.com) that let you log in your activities. Some of the sites calculate the number of calories burned by taking your weight (the more you weigh, the more you burn) and the speed or the intensity at which you worked along with the number of minutes you worked out.

My elliptical does not take my weight into consideration and I found I was actually burning a few more calories than what it listed!

as long as th machine asks your weight it is pretty close in the estimate... its never 100% but i would say 98% correct