--Kindles Are Everywhere: People seem to love to read on these things on the beach and at the pool. Mostly guys in the 45 to 64 demographic.
--The iPad is Perfect for Vacations: At various times the iPad served to: a) entertain kids with movies and games on long car rides, b) as an easy way to delete e-mail (to lessen e-mail pileup), without the motivation to respond, and c) to download and play Banagrams. 
--The iPad is Too Heavy to Read With. My brother's Kindle DX provided a better reading experience solely based on weight.
--WiFi is Like Oxygen to a 23 Year Old: Beach house had DSL and WiFi, which was heavily used by my brother and his girlfriend. They worked (see below), but also searched for information, listened to music, and communicated with co-workers and friends. Their laptops were attached to them like a new evolved appendage.
--Millennial's Do Not Distinguish Between Work and Play: Watching my brother and his girlfriend for a week left me with the distinct impression that the old model of a "workplace" and a "home place" is just not going to work for his generation. Even the distinction between "vacation" and "work" seems to break down. As far as I could tell, they were both incredibly productive - while being social (with their laptops), and still making time for beach walks and bike rides. The millennial generation will finally kill the old factory model of work and school (good riddance!).
--Old Fashion Paper Books Equal Relaxation: While my family was playing Banagrams or Skyping or whatever, I read two amazing books - The Next Hundred Million: America in 2050 , by Joel Kotkin and Next Stop, Reloville: Life Inside America's New Rootless Professional Class , by Peter T. Kilborn. Maybe a Kindle would have been okay, but the paper experience would have been hard to beat. I'll go Kindle when I can get an e-book as easily from my College library as a paper copy.
--Audiobooks are Essential for Long Drives: Finished up This Book Is Overdue!: How Librarians and Cybrarians Can Save Us All,  by Marilyn Johnson (look forward to discussing), and almost completed the wonderful, Potato: A History of the Propitious Esculent , by John Reader. Is it legal to wear headphone (or one earbud) while driving?
What are some of your vacation tech observations?