I use the free Web page watch service at changenotes.com to monitor certain mission-critical software sites for updates, monitor the HandStory site for new release info, and other places where I'd like to know if something's been added or changed but don't want to keep going there to check!
If you're interested, it's at
www.changenotes.com and works by sending you a dailing e-mail with the links to sites you've added to your account with changenotes. It's a free service (ads appear in the e-mails), and I suspect it may have third-party spyware as well used by the third-party advertisers (changenotes privacy policy hints at this), although it's hard to tell. I use ZoneAlarm and block this type of activity, so it's not an issue for me.
Very useful service, and I'm sure there are other sites out there that do the same thing.
Anyone using a different site watch service?