Thanks to Marcia Connor for pointing out this Periodic Table of Visualization Methods (via a long chain of retweets). I was explaining to someone the other day about Mind Maps, and how they’re a particular type of visualization technique. There are even special-purpose programs that you can use to make some of these diagrams.
For basic diagramming needs, I use OmniGraffle on my Mac Powerbook, and I love it. For WIndows users unaccustomed to such things, it’s a lot like Visio.

Responding to Infoworld 
Solar cells on an outhouse? Yup. In the coastal headlands of Marin County.
Approaching the cash register at Starbucks I noticed this perhaps puzzling message on the little LCD display. It has nothing to do with the economic meltdown, or the amount of cash in the cash drawer, but instead reflects a programming error!