A side note about powells.com:
If you've spent much time on the web site, you'll notice that someone at Powell's Books has an inordinate fondness for Pokey the Penguin. At the end of each URL, you'll see the following:
I emailed the webmaster about this as soon as I discovered Pokey the Penguin. Was this really a reference to the comic strip, and why on earth was it being appended to the URL anyhow?
The answer: Yes, a former web programmer was a big fan of Pokey. Setting pokey to "skeptopotamus" allows a cookie to record where you've been so that you can resume searching from where you left off.
Now you know... and knowing is half the battle!
(qousqous has another take on this at Powell's and Pokey.)