I've just added an RSS feed to kernel.org for tracking the latest kernel versions. This is the same information as what's on the main page, but now it can appear in your RSS aggregator. ;)A Atom Feed would be great too :)
Please set your refresh rate higher than normal; no one needs to check every hour for a new kernel. :)
The direct URL is http://kernel.org/kdist/rss.xml
Have fun!