For my X100, I feel the Manfrotto Nano VII was the absolutely perfect bag. Camera fit in their snug with the lens hood, and the pouch in the front had just enough room to squeeze in an extra battery, and memory card. I'm not concerned with bumps/drop protection as I am with overall scratches, weather, and ease of carrying.
http://www.manfrotto.com/nano-vii-camera-pouch-black

For the X-Pro1, I recently picked up a Domke FXA. Seemed like the smallest bag I could find, but IMO it's still a bit too big.
http://www.amazon.com/Domke-700-51S-F-5XA-Small-Shoulder/dp/B000PHTVK8/ref=sr_1_1?s=electronics&ie=UTF8&qid=1335320800&sr=1-1
Here it is when compared to the Manfrotto

And here's the inside. Picture doesn't really show just how much extra room is left. I could easily cram the x100, batteries, charger, and extra cards in it.

Anyone have anything smaller? Ideally I'm looking for something that will fit just the X-Pro1, 18, and 35mm lenses. That's it.

















