I'm taking a couple of days off pre-Macworld Expo and while chilling down in Florida with my family my wife suggested looking for an iPhone app that played Auld Lang Syne and/or had a New Year's Eve countdown timer. I find them all rolled into one – for free.
New Year's Blowout Horn! (iTunes, free) is a fun little iPhone app to help you ring in 2009. It combines a countdown timer (to NYE obviously) and a blow-up noisemaker that you engage by blowing into the iPhone microphone (think Ocarina). It also plays Auld Lange Syne at the stroke of midnight or when you click on the "i" icon.
The perfect combination of silly and free.