Simon Rich - Free Range Chickens
This is free on the Stanza reader app on your iPhone or Touch. Also free on Amazon's Kindle. VERY funny, short 'essays'.
Jeff Kinney - Diary of a Wimpy Kid: The Last Straw
If you like humor, you owe yourself a favor to read this Wimpy Kid series. It's for young adult readers but if you've ever been that tortured, nerdy soul growing up and then got your confidence, this is HILARIOUS. We reserved this at the library at my 6 year old daughter and I fought to see who could read it first. She won.
I laughed hard, out loud in the first 15 pages. The Shel Silverstein reference made me laugh for a long time. This is the 3rd of the series. HIGHLY recommended for the whole family.
Also got our first Kindle 2. Still learning it, cool gadget. Not necessarily the most cost efficient device, but it can be very useful for a long vacation with a kid who reads 3 books/day.