I always pack chargers in my carryon. However, I keep chargers for both my husband's phone and my iPhone in our Owner's Locker, along with a charger for my camera battery (which is a tiny brick that plugs right into the outlet, no cord). That said, here's what I do for us. I make sure DH's phone is fully charged. It doesn't get used much at all since it's a very, very basic phone (he isn't allowed to have a smart phone or even one with a camera due to security where he works). I pack my laptop, my laptop charger and a tiny,
retractable USB-to-iPhone cable. (Yes, under $3.50 each! Don't let the price fool you - these are awesome.) I also pack my
Brookstone iPhone backup battery after it's fully charged, too. That way anything can run off my laptop at the airport or hotel and if I need charge for my iPhone on the plane, I can use the laptop or the battery extender. And the battery extender comes with a small power cable that plugs into the wall or into the laptop via USB, so I can charge directly from the wall if I need to.
Finally, the other item I almost always travel with is this Belkin 3 outlet, 2 USB
Travel Surge Protector. If you are in the airport and it's crowded or flights are delayed, this can come in handy on the hunt for a free outlet, and gives you a little bargaining power if you find no outlets free, too.
(Sorry, I know this wasn't a thread about travel electronics, but when I got started, I couldn't help myself!

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I don't really worry about cables in my luggage - I don't pack anything of real value in there, so if someone saw cables and got interested, they'd be disappointed to find just a mixture of 3 people's clothes and some sunscreen!