This is another excellent and creative way to use RSS. Greg Reinacker has posted an ASP.NET solution that will let you ask for exactly what you want. E.g.:

http://example.org/Rss.aspx?num=20&logs=Application,System

Will get you the most recent 20 entries from the Application and System logs. Very nice. I will probably install this on the servers I have hosted at a data center. Sure is easier than other remote monitoring I've seen, and it uses a channel that I'm in a few times a day.