Hi : i like to monitor changes to one of my sharepoint site's load over time . its a production site so i dont want to populate test data or hit the site with test requests. Is there other ways you can suggest? Thanks

It's not completely clear what you want to achieve, but if I understand correctly you want to measure page load times? If so, in my opinion, doing such measurements (and other tests) can be done best by using Visual Studio Team Suite (or just the Test Edition). You can define the amount of test requests done to limit the amount of load on your production environment, while still getting useful output.