The Fire Seekers (Book One of the Babel Trilogy) will be published by Skyscape on November 1st, 2014, but you can pre-order it on Amazon now. It's a thriller about the origin of civilization, the meaning of life, and who's trying to wipe us out, among other things. It will seriously mess with your head.
Emperors of the Ice is now available both in the original hardback (with four maps and over 70 photographs) and as an e-book. It won both an 'Outstanding Book' designation from the National Science Teachers Association and a Washington State Book Award; reviewers have described it as "an enthralling tale," and "so gripping you will not want to put it down."
You Are Here: A User's Guide to the Universe is a short tourist guide to absolutely everything. It's now available both as a paperback and as an e-book.
The Truth About Constance Weaver got a wee bit delayed, but is on its way soon. Read about it, along with notes on some other work in progress, here.