Checkurls is a files changes checker.
It can help you reduce the time you lose checking for updates, and lets you to read only the new things.
It monitors a list of files, and if a file changed it sends the changes to you by email, so you can use your preferred mail user agent to read them.
It has options to report only the added text, only the removed text, both, HTML to Plain-Text redering, minimum and maximum lines to report.
I tested Checkurls on GNU/Linux, but it should work without many problems on similar systems, it needs an UNIX-like environment and these programs: mail, wget, getopt, lynx, diff, grep, wc, tr, tail, head.
You can download Checkurls from: <http://savannah.nongnu.org/files/?group=checkurls>.
The development area is located at: <http://savannah.nongnu.org/projects/checkurls>.