I finally got my copy of A Treasure's Trove from Amazon, and have started to hunt through it for clues. There are two sites dedicated to helping readers share clues and find the treasures: 12Gems and Tweleve (not a typo). An interesting article in Wired describes how these sites are allowing readers to network and form giant problem-solving machines, cracking puzzles far quicker than in the past. Thankfully, in spite of all this activity, none of the gems have been found so far. This blog claims a complete solution, but I've heard that it is bogus.
This is the second in a series of blog entries: here is part 3.