There are plenty of ways to get around restrictive carry-on weight restrictions - including custom-built "luggage jackets." My current preference is a pair of cargo pants and a jacket with decent sized pockets, but cargo pants need a belt, which means delays at the security checkpoint.
So, I've been theorising about using a photographer's vest for my next trip: something like this
Pros
- Heaps of pockets
- Easy to get on/off
- Pockets big enough for paperbacks

Cons
- Geeky
- Suspicious to security?

Anybody have experience using a photographer's vest?