In no particular order:

• Airports & airport security. Food courts and choices at airports, especially as I think they over charge. (Is their rent that expensive?)
• Airplanes. Being crammed into a small seat with no legroom for ~4 hours, I always seem to hurt my shoulder somehow twisting around.
• Being out of the loop on the outside world. I find when I travel, and work across the country, between being busy in the office, and then dinners with co-workers, I miss the news on TV and the internet.
• Hotels. I never sleep well anymore. I did when I was younger.
• Hotel showers. I hate their shower heads.
• My feedreader explodes. I don’t have time to browse the internet, and my feedreader has hundreds of items to catch up.
• Red-eye flights. Enough said.
• Getting home, tired, and not having the proper energy to spend with the kids and / or wife. Lots of guilt over this one.
• Catching up on my DVR. See feedreader above.