I spent a month walking across Spain in a technical fabric t-shirt. The material kept me cool, and it dried quickly after washing it every evening, but they're far from flattering. And the lack of a collar made me feel a little underdressed on the rare occasion that I'd wander into town and want to eat somewhere a little nicer than the bar closest to where I was hanging my pack for the night.
When I found out that Sierra Designs made a lightweight, breathable polo-style shirt from a wicking technical material (100% Polyester inter-lock knit, 1.5% anti-odor bamboo, wicking finish.) It's difficult to pull the threads and after four months of wear, I have yet to notice any pilling. It's a good quality piece of kit. What's more, the material offers an SPF rating of 30, has a chest pocket designed not to interfere with backpack shoulder straps and the collar can be flipped up and buttoned into place to provide the wearer's neck with some wind or sun protection.
These last few weeks, I've been housesitting in LA, where the temperature has peaked at 34°C during the day. I've gotta say that I'm happy I brought the Pack Polo along: it's kept me a little cooler and a whole lot more comfortable than any of the other travel shirts I stuffed in my bag for the trip. For my next warm weather trip, I'd definitely consider buying a few more. Even at close to $70, they're worth the investment.