I often talk about adding personality to your app, including turning negatives (like downtime) into semi-positives, as with the Flickr example.  Here’s what Twitter looks like right now:

Maybe it’s because Twitter’s been down a bunch lately, or maybe it’s because I really don’t like cats, but when I saw this I thought “I’m really tired of this little trend.”  I long for the good old days of not trying to be cute when you screw up.  Just say “We’re down.  We’re sorry. We’re working on it.”