I have found the following link for rooting several Android devices: link text It seems quite easy to root, but how difficult is it to go back to unrooted once you've rooted?

I'm thinking about unrooting and going back to completely stock, vanilla Android on my Droid. How can I do this?

Once a device has been rooted, is it possible to unroot? I also want to keep my data, so can I unroot without wiping/re-imaging? If so, how difficult is this?