From MediaPost:
Google Labs is testing an "undo" button on Gmail that gives you 30 seconds to stop an email from reaching its recipient. If they extended it to a 30-minutes hold, I might switch over to Gmail. Thirty seconds is simply not long enough for me to calm down, take a breath, think about how I really feel, and then go "Oh shit!" as it dawns on me how intemperate my reaction was. Unfortunately, no amount of time will compensate for some of the truly stupid, hurtful stuff I say and write, but it would be great to be able to recall emails (or snail mail) sent in an unguarded moment.
While one might argue that email, tweets and texting have somehow increased our productivity, giving us the ability to reach out to scores with the same message, there has been a noticeable degradation in the formation and maintenance of business contacts, since there is little time for simply being "social" and learning a little more about each other beyond "When will I get the RFP back?" The let's-get-together-over-lunch-and-discuss generation is shuffling off this mortal coil at an increasingly rapid rate.