Israeli developers just unveiled new software that can out depressed bloggers using sentiment analysis. After initial testing, the software pegged about 80% of the bloggers correctly. 

"A psychologist knows how to spot various emotional states through intuition," Yair Neuman, Professor at Ben-Gurion University, told Haaretz. "Here we have a program that does this methodologically through the innovative use of 'web intelligence.'"

In addition to automatically scouring the web for bloggers in need of help, this kind of sentiment analysis could be used to spot other emotionally-driven writing. There are a variety of uses I can imagine:

• For marketers to spot early trends
• For parents to monitor their kids (and their kids' friends)
• For competitive intelligence/ corporate research
• To evaluate your relationships
• To detect future political hotspots

Very exciting stuff. Read more over at Haaretz.