This idea was taken about a gazillion steps further in Lanvin's Fall 2013 show, with their line of wordy statement necklaces. They used words like "happy" and "cool" in a script font, and scaled the proportions way up. I really like the look:
Is this cool? Yes. Is this a new idea? Not really. Look at this Chanel necklace from 1994:
There are some options if you don't want something quite so large, like this sweet necklace from Dior, in white gold with a diamond:
Or if Dior is out of your price bracket (or on another price planet, as it is in my case), there's tons of reasonably priced options from the handmade side of Etsy, like this sweet "happy" necklace from Piano Bench Designs, available here.