If you're one of those "just a camera over my shoulder" folks, but want a small pouch to hold your camera in transit, check out the Delsey GoPix 20. It's a perfect carry pouch for a body and lens. I rarely carry it while shooting; but it's very often where my camera lives when it's not working.
It's lightly padded, has a zip top on it's one pocket; loops on the back allow you to put it on a belt, and it has a thin shoulder strap that attaches with clips- that's it. I can cram a surprising amount of gear in this thing. An M body and a 50 DR, maybe shove in a CV 21 Skopar, and a small meter, and shove this in my carry on when I fly.