Ooooh I love this vest. Seriously, it might be illegal in some states how much I love this vest. I first got it for my birthday in June 2008. So into my closet it went for nearly six months while I waited for the temperature to drop enough for me to wear it.
Finally, it did and ohmygosh most amazing article of clothing ever. It's got tons of pockets for my iPhone, tissues, extra gloves, keys, anything. And the fit - oh the fit. I buy this vest in size Medium and it fits me absolutely perfectly - as if the L.L. Bean designers snuck into my room, measured me, and then designed the vest with my measurements in mind. It fits nice and snug but not too tight. I've got plenty of room to breathe and move. It's made of wicking fabric so it pulls the sweat and moisture away from your body while you run and since it is a fleece material, it also keeps me snuggly warm!
Typically I layer this vest over a long sleeved technical t-shirt. If it's raining, I put on my Nike rain windbreaker (similiar here - I got mine off the Dick Sporting Goods clearance rack in January 2008) which provides no warmth but does provide extra protection from the elements.
Over the summer, during my vacation to Alaska, I wore my vest over a tank top for extra core warmth during a mountain hike. See - it's versatile too! (This is just one of three photos of me with animal statutes in Sitka, Alaska - oh I do amuse myself!)
I asked for, and received, a second vest for Christmas this past year (in Tidal Teal - pretty pretty!) then a few weeks later I noticed that the vest was on sale for $22 each! I snagged two more immediately (in Black and Meadow Violet). The next day the price was back up to $39 so somebody running the website must have messed up big time - hehehe not before I got two new vests though!
Of course for serious cold weather running (I'd say anything below freezing), you should definitely invest in a running jacket (mine is similiar to this), but for less frigid days, this vest is absolute perfection!