My current bag is a Vancouver 2010 Winter Olympic Games messenger bag. The body of it is one large pocket, big enough to hold my laptop, necessary cables & a 3 inch binder. It does also have a small mesh pocket at the top, large enough for an iPhone, but I often use it for change, keys, and business cards.
I used to have a Dickies brand messenger bag that I loved that had a bunch of pockets, but I like having it all in one pockets.
Also, it was extremely discounted because I worked for the games. I think I paid $15 for it.