Particletree has an informative article on Fitt’s Law, an important guideline in user-interface design.
Published in 1954, Fitts’s Law is an effective method of modeling the relationship of a very specific, yet common situation in interface design. That situation involves a human-powered appendage at rest (whether it’s physical like your finger or virtual like a mouse cursor) and a target area that’s located somewhere else.
- Link (via UNEASYsilence)