I don't remember how I came across this image, but I copied it and kept it because I think it entertains while giving bad news.
When you have to give your customers a bad piece of news (we're down! our site is under maintenance! we're dead in the water!), at least make it relevant so that the experience is a little more than an impersonal kiss off.
The Twitter Fail Whale is probably the best example of this; I don't know if that directly inspired Spiceworks to come up with this image, but it does the job very nicely.