I just started reading Professional Twitter Development: With Examples in .NET 3.5 (Wrox Programmer to Programmer) and came across this quote, which cracked me up:
The Twitter API is the Schrödinger’s cat of web service APIs. Until you call it, you never know if it's alive or dead. Sometimes the mere act of calling it is enough to kill it.
--Scott Koon,Witty
Hilarious. And true.