In addition to the probably already heavy pile of batteries and charging/powering devices you're planning to haul along, here are some related items to consider packing:
Phone line tester. such as iGo's Road Warrior Modem Saver.
Power/surge strips/cubes. While bulkier than I'd prefer, Belkin's 7-, 8-, or 9-outlet surge strips, or Tripp Lite's 7-outlet SUPER7TEL Protect It! Surge Suppressor power strip, can accommodate enough AC transformers.
If space is at a premium, consider something like Tripp Lite's Traveler Protect It! Surge Suppressor, with 2 AC outlets plus phone jacks.
To surge-protect just your notebook, choices include APC's SurgeArrest Notebook, Belkin's Universal Travel Surge Protector, or Tripp Lite's TRAVELERC8. Make sure that you get the right modelin terms of 2- or 3-prongfor your computer.
Concerned about surges on the hotel Ethernet? Splurge a little ($3040) for something like an APC ProtectNet data line surge suppressor.
In case you encounter two-prong outlets, it never hurts to have one or two 3-to-2 AC adapters along. They're cheap (under a buck) and small.