You guys ever notice that when Artoo aproaches our heroes with Obi Wan's message after Shmi's funeral, the next scene shows them listening to said message in Padme's ship and Threepio is inexplicably with them, then they take off to rescue Obi Wan, and they just take Threepio with them? Not a word to the Lars, not a goodbye, not a hey, we're borrowing your driod, nuthin!! Not only is Anakin a mass murderer, but a thief as well! For shame, Anakin! All joking aside, I'm sure we can assume that in the "negative space" between scenes, Anakin bid farewell to the Lars and basically said "Yo, I built this droid, I'm taking it with me" and they let him, because Anakin is scary, and because 3PO annoyed them anyway. At any rate, I woulda liked a little scene showing this imagined goodbye, with Owen and Anakin kinda displaying a bad vibe between them. You know, just to show the roots of Owen's dislike of Anakin that he displayed in A New Hope. It woulda been cool if that dislike would have been right from the get go, i.e. Owen just doesn't like Anakin from the start, and that the feeling is mutual. As is, the Lars' screentime was very minimal, and a small scene like that wouldn't have hurt.