One of the new features that Apple introduced in the iPhone 4 was HD video recording, allowing users to capture 720p video from their handsets. It's a great new feature, but hackers have found a way to enable that feature on the iPhone 3GS.
It seems that iPhone 3GS with its similar CPU and GPU has enough power to pull HD video from the 3 megapixel sensor in the main camera.
Those who have iPhone 3GS and are adventurous enough to jailbreak and dive into the system files can turn on video recording at 1080×800 at 30fps at up to 20Mbps, which is a huge jump over the default 640×480 at 3Mbps.
Check out Redmond Pie for the procedure if you want to get some new tricks from that older iPhone.