We're big fans of packing light here at Practical Travel Gear, which means taking clothing that can work in multiple situations and climates. I've taken this ExO Dri 1/4-zip shirt from ExOfficio pretty much every time I've packed a bag in the last four months, so it's definitely a keeper.
This is one of those do-it-all travel shirts that more than pulls its weight---and it only weighs a few ounces. First, the features: quick-drying, odor resistant, wicking, sun-protecting, and very wrinkle-resistant. So it doesn't get stinky when you've worn it for three days, but when you finally get around to washing it in a sink it'll be dry in a few hours. When I work up a sweat in this ExO Dri shirt, it's gone in jiffy after I cool off. (If you care about the specs, it's treated with dri release and FreshGuard.)
None of that matters if it's not comfortable, but fortunately this shirt feels great. It's not clingy and it feels as soft as cotton. After about 30 washings, it feels the same as it did when I got it and hasn't lost any color.
There are three colors of this on the ExOfficio site, but oddly enough not the one I have in Jade Green. That color is on sale at Backcountry though. This long-sleeve shirt lists for $48, but it's on sale right now for almost a third less as we head into warmer weather.
* Editor's update 10/10/12 - This shirt has been revamped a bit and now has the word Carbonite in its name. This refers to the coconut husk material used in the fabric, which helps prevent odor. List price is now $60, links have been updated. The old version is still available via the Backcountry link in the previous paragraph.
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