If you're using the CyanogenMod team's custom ROM on your Android device, and are running any of the nightlies from today (Sep. 30) onward, you now have a new option in your settings -- CM Updater. What it does is give you the option to automatically check for updates and install then, just like an over the air update from your carrier. We've seen this done before from other developers, and from ROM Manager, but now there's a built in option for all users of the ROM.
It's worth noting that this only checks for and installs updates to CM 10. It doesn't replace a custom recovery, so you'll need ClockWorkMod recovery installed to use it. It also doesn't update any Google Apps, so you're on your own for those.
To find the feature, make sure you have the latest nightly build, and look in Settings > About phone > CyanogenMod updates. You can choose from a few different options, including whether or not you only want to stay on the stable release track. Everything seemed to go fine in our quick testing using tonight's nightly build for the Galaxy S3, but keep in mind that this is not a finished product yet, so there may be bugs.
Anyone giving this a try? Sound off in the comments to let everyone else know how it goes for you. If you hit any snags, hit the forums to hash it all out.