There was some criticism of GL having Anakin 'make' C3PO in TPM. I thought it was a bit odd at the time, but there is a level of symbolism that I had missed then. Anakin is fatherless, but builds Threepio to 'help Mum' (like a father would?). Anakin leaves Threepio behind when he joins the Jedi. At this point Obi-Wan becomes his 'father'. In AOTC when Anakin meets up with Threepio again, it is without Obi-Wan. Is it coincidence that Anakin is never with Obi-Wan and Threepio at the same time? Onto Padme. R2D2 is her droid. Artoo is with her throughout TPM (except when Artoo accompanies Anakin in space) and again in AOTC. In fact Artoo saves her life on a couple of occasions - and tries to in her bedroom. We don't know the content of Episode III yet, but interestingly, the two droids take similar roles with the twins. Aboard Tantive V, Artoo is Leia's guardian - only disappearing when she is in the presence of her real father Anakin. On Tatooine, the droids show up right about the time that Luke loses his foster parents, Owen and Beru. Throughout the original trilogy, the droids are accompanying the twins. The only exceptions that I can think of (Threepio staying with Chewie when Lando takes Leia and Han for a drink (ESB), Artoo having a door closed on him (ESB), Leia's imprisonment aboard the Death Star (ANH)) - are at the precise moments that they are in the presence of their real father, Anakin. That GL decided that Anakin should build C3PO helps this symbolism enormously as the droids may in fact be 'stand-ins' for Padme and Anakin in the OT.