For the last couple of years I've been wearing a Björnkläder Jubilee Carpenter's Tool Vest. I got it because it has better storage options than traditional tool belts.
I dislike wearing tool belts because they're bulky and the tools hang out and scratch finish surfaces, so for most of my career I worked in cargo pants with the pockets stuffed full of tools and supplies. The problem was, they didn't hold everything I needed and I was always searching for tools I had put down somewhere.
The vest has been great; it has a ton of pockets and specialized features that allow me to carry everything I need and still be comfortable. The tools are easy to get at and can be spread all over so they don't stick out from around my waist. If there's a trick to using a vest with so many pockets it's to put the same tools the same place every time; that way, you won't have to think about where they are.
The vest sells for about $100. It's not cheap, but worth it for a piece of equipment you use every day. Björnkläder gear is not widely distributed in the U.S. I order it from Faceline but you can also get it from J&R Distributors.
Click the photo on the left to see the details of the vest and what I carry where. Greg DiBernardo covered Björnkläder pants in an earlier article.