Which website monitoring services do you use?

[TracerX]

Hey all,

I've been keeping up with sites on list that is growing increasingly larger.  Do any of you use site-monitoring services to notify you of changes in site you follow?  Google returns a ma-jillion entries, so I was hoping to get some feedback from this forum.

I'm looking for something that will email me, perhaps in daily digest format, of sites that have changed--it doesn't have to show me the actual delta, I just want to know if there has been a change.

Cheers.