This is the cycle of authors named Steve who publish with their middle initial.
22. Freakonomics by Steven D. Levitt and Stephen J. Dubner
These two Steves ramble around studying numbers and looking at wacky correlations of data about crime, sumo wrestling and other things that seem unconnected. The Steves do a decent job of hammering home that correlation != causation while doing a decent job of trying to find actual causes. A decent read, and much quicker to get through than I expected. I hated the end note style - notes were unreferenced in the text, so you had to go flip to the end of the book and see if they put in a note for the fact you wanted to check.
23. Ariel by Steven R. Boyett
A boy and his unicorn in a fairy tale post-apocalyptic world. I'm looking forward to the sequel.