One of the difficult choices you have when travelling for a year is what to bring and what to leave behind. When travelling for a 2 week trip, you usually try to make sure that you will not have to do any laundry. However, for a year long trip, you cannot bring 365 T-Shirts.
That being said, I was looking for a shirt that I could wear more than 1 day and that was easy to wash. Looking around, I found two options:1) Exofficio who's slogan is: "17 Countries. 6 weeks and 1 pair of underwear. Okay, maybe two"
2) Merino Wool: Merino Wool - Odor Control In order to choose what I would bring, I put the T-Shirts to the test: Monday, I wore the shirt to work and to a volleyball game. Wednesday, I wore the same shirt to another volleyball game. Thursday I played Racquetball and volleyball. After all that, neither shirt smelled bad.... that is impressive.At the end of the day, I choose the Merino shirt because they offer more variety than the Exofficio. The only problem with the Merino shirt is the price: A T-Shirt costs between $45 and $95.
Update (August 31st 2012): After 3 months of traveling, we prefer Merino Wool. The main reason is that it really holds to its oderless reputation. The only drawback we found is that sometimes it gets little holes.