Supporting a "print friendly" capability is very useful for readers who like to print out longer articles and web pages. Using a cascading stylesheet tuned for print media is a simple but effective way to add this capability without creating special print-friendly templates. I wrote a short article describing some of the details, including examples for MovableType:
Print Stylesheets
Mobile Websites
As a side project, I maintain a popular list of mobile websites on cantoni.mobi.