Originally Posted by BLI-Flyer
Bring an extra battery for the laptop.
A lot of people here would consider that to just be extra weight. Instead, bring your charger, charge it up between flights & if you're going internationally, carry the plug adapter for the country you're going to - most laptop chargers have inverters built in (as do most portable DVD players & digital cameras) so you just need the plug adapter.
See this thread -
http://www.flyertalk.com/forum/showthread.php?t=277896 - for more on a long MR checklist.
I think the OP was referring to what goes into planning a MR, not necessarily what goes into the carry-on for the MR.