nitoTV on your Apple TV used to involve a mildly difficult SSH process, and for those folks who are turned off by running Terminal and punching in lines of code, the newest version of greenpois0n (RC6) might pique your jailbreak interests. It'll perform an untethered jailbreak (meaning, you can reboot your iProduct without the need to re-JB), freeing your device (iPhone, iPad, etc.) running 4.2.1 and allow you to fulfill all of your out-of-jail needs. Bundled in this new release is a loader that'll inject nitoTV right onto your little black Apple box. This new greenpois0n is said to fix emulation problems (zodttd's emulators were having issues) and can be applied right over your device that's been freed with RC5. But proceed with caution -- we're seeing a bunch of jailbreakers on Twitter claiming have ran into issues (WiFi, booting) with RC6. Hit the source link to grab either the Mac or Windows version.
[Thanks to everyone who sent this in]