Keyboarding vs Handwriting, and how they affect our thinking

Clive Thompson over at Collision Detection cites a New York Times article about a study of handwriting vs keyboading by students.

Computers have drastically reduced the amount a student writes by hand, so much that the skill, "like an unused muscle", is pretty much dead by your senior year. But there's an interesting question buried in this piece: What is the cognitive effect of handwriting versus typing? (referring to a NYT article)

Then he goes on to ask:

"For me, there's an even deeper question: Are there any qualitative differences -- in the way you think, create, or express yourself -- between handwriting and typing?"