Ok, I admit it, the computer has reduced my attention span. I try to pretend it hasn't, but the fact is that I read in much smaller chunks than I used to, and I can't ignore the demands of email, even if it's just to delete a fragment of spam.
This article in the New York Times (registration required) suggests there might soon be a way in which our computers will be able to protect us from the very distractions which it has created in the first place...