Not everyone can upgrade to an iPhone 3GS. Everyone can, however, record video.
Cycorder's been one of the best reasons to jailbreak iPhones since the beginning, and it still makes a convincing argument. Video quality is fine, considering that the iPhone's sensor wasn't even designed for it.
From the App Developers: Record at the maximum speed of the iPhone Camera (6-15 frames per second, depending on lighting conditions) with no compression delay between pressing stop and getting to view the resulting video.