Logo Lounge has a good piece on logo trends from 2007:
Charlie the Tuna and the Jolly Green Giant, these are not. Advertising characters have danced the line between logos and mascot for years. Even the Cingular Jack was a bit of a hybrid with a personality that animation played out beyond the printed page. Urban vinyl is a subculture that is starting to cross over into logo design. These small vinyl characters are ubiquitous shelf clutter, enshrined in nearly every designerís desk collection.First made popular in Hong Kong by Michael Lau in the 90’s, these imaginative imps have become highly collectable and have entire stores, KidRobot and magazines, Super 7, dedicated to their notoriety. The art of Tim Biskup may start on canvas but it soon translates to designer vinyl characters. Usually they can be as mundane as fire breathers to as outlandish as slimy cyclops ghost aliens. Though not a serious influence on Fortune 500 identities, urban vinyl has its place in pop culture, and that has translated to two-dimensional applications in logo design.
(via Kottke)