For those tiny seeds that are hard not to sow too thickly, like carrots and radishes, use one of the large spice shakers you buy at the store. After it's empty, wash thoroughly and dry. Add your seeds and shake gently.
As a carrier for the seed, and that also lets you see where you have planted. Additional plus, if your seedlings are slug-bait, they allegedly don't like to crawl across the sand (although I've never found that to be much of a deterrent...)
I want to live in a world where the chicken can cross the road without its motives being questioned.