It's amazing what happens if you go searching Amazon.com for the word "OpenWrt"; it seems that we're mentioned in a few publications. I really wasn't expecting much, and indeed the first publication is nothing more than a footnote in "Wireless Hacking: Projects for Wi-Fi Enthusiasts" from 2004, but then things got interesting: "Hacking Roomba: ExtremeTech" from 2006 seems to have a section on OpenWrt -- I'm confused.
The latest in this trifica seems to be the just-now-released "Linksys WRT54G Ultimate Hacking" which claims "Full coverage on embedded device development using the WRT54G and OpenWRT". Spiffy.