But I have a new favorite, qTweeter, developed by the folks at Efiko Software. You won't find it in the App Store, though, because this app requires a jailbroken device. Multitasking isn't officially allowed (yet?) on the iPhone OS, yet qTweeter relies on this capability to perform its best trick.
Say you're checking the weather and want to tell everyone of the approaching hurricane. Normally, you would close your weather application, swipe through pages of apps, tap on and wait for your favorite Twitter client to open and load all of the tweets that you really don't care about right now, and finally type your warning to get the heck out of town. By the time you do all of that, the highway is going to be grid-locked with fleeing residents and you'll be stuck boarding up windows and sweeping up the debris!
Instead, you could have just "pulled" qTweeter down from the status bar, typed your tweet, and went back to the app still running in the background.
In fact, per the recent trend, you could have also posted that same message to your Facebook status with just a tap of a checkbox. It's a much quicker way to get your message out of your head and onto the Net, a fact that you'll appreciate as you get older and those thoughts become more fleeting.