Chronic Dev Team has released a jailbreak tool on the Cydia app store for those who have already installed a tethered jailbreak on their iOS 5.0.1 devices. Using this tool, called Corona 5.0.1 Untether will modify your iPhone with the same exploits used in redsn0w. Unlike the redsn0w jailbreak process, Corona requires no computer to untether a jailbroken device.
In order to successfully install Corona, your iOS device must already have a tethered jailbreak installed along with iOS 5.0.1. Do not use Corona if you're using a hybrid iOS 5.0/5.0.1 jailbreak! This requires installing and running redsn0w after a clean restore to stock iOS 5.0.1.