CyanogenMod 10 gets OTA nightly builds installed automatically with new CM Updater option
The team added a feature to About->Settings called CM Updater, which will connect to their servers, check for the latest nightly download, and install it on your device on request - it doesn't get any easier than that.
CM Updater will work for all the nightlies that appear from today onwards, but bear in mind that this is for stock CM10 only, it won't update your custom recovery, so you'd have to resort to ClockWorkMod for that.
It also won't update your Google apps, you'd have to do it manually, but these are a small price to pay for having OTA CM10 nightlies delivered to you automatically.
source: CM (G+)