New Balance has a tank called a Skye that comes in different colors. It is a bra tank that has 3 pockets in the back and one is even zippered. I have one in every color they make (light blue, teal, garnet, and green). They run about $29.95 at my local store.
Brooks makes a shirt with a small zipper pocket on the lower left side. Not sure what it's called, but I have two of them and the pocket is a great size for a room key when I travel.
I checked when I got done running today and I also have a Nike long bra top that has 1 pocket in the back and I have a tank that I think was a tennis top that has a zipper pocket in the back. If you are looking for LS tops, I have a couple New Balance and 2 heavier Activa tops that have iPod/MP3 pocket in the sleeve which are pretty handy too. I think the Activa, Nike and the tennis shirt all came from Dicks Sporting Goods on the clearance rack.