About the only really useful hint here is to turn off notifications. I tried out Growl when I first got my mini, but after a few weeks I realized it was adversly effecting my productivity, bouncing between email, IRC and IMs almost constantly. Minimalist screens, docks, etc. are a matter of taste but I don't seen any real productivity improvements.
That's exactly what I expected too, and while I certainly turn it off when deep in the zone, I found there's a certain sweet spot where growl actually minimises distractions because you're vaguely aware of what new message/mail/etc just turned up, but don't need to toggle applications to see if it's worth paying attention to.