iOS 5
Even if you were one of those Apple fans who was less than impressed by the iPhone 4S, there is still reason for excitement -- and that reason's name is iOS 5. If you've got an iPhone 3GS, 4, third- or fourth-gen iPod touch, or either of the iPads you can download Apple's latest and greatest mobile OS right now. That's right, all the fun new features like pull-down notifications, iCloud, iMessage, Find my Friends, Twitter integration and lock screen access to your camera will be at your disposal. Sadly you will not be getting a taste of Siri, which appears to a 4S only feature for now. Still, there's more than enough here to make it a worthy upgrade to your device. So, what are you waiting for? Go hit that update button now.

Update: Just so you're aware, you'll need iTunes 10.5 installed to get the latest iOS. There's also an update to OS X coming down the pipes -- version 10.7.2 -- which officially delivers iCloud to your Mac. Huzzah!

[Thanks to everyone who sent this in]