From MSNBC News:
You may or may not have pondered why your breakfast cereal tends to clump together or cling to the sides of a bowl of milk. Now there is an easy explanation. Dubbed the Cheerio Effect by scientists, this clumping phenomenon applies to anything that floats, including fizzy soda bubbles and hair particles in water after a morning shave. Dominic Vella, a graduate student now at Cambridge University, and L. Mahadevan, a mathematician from Harvard University, decided to change that. In a study that appears in the Sept. 15 issue of the American Journal of Physics, Mahadevan explains the Cheerio Effect using three basic concepts from physics: buoyancy, surface tension and the meniscus effect.
More here.