Or, if you wanted to work it into all three prequel films...
Places to include a rickroll:
Ep.1
- when Obi-Wan points to the screen aboard the Queen's ship and says, "Look, Master... Tatooine" (cut out the "tatooine)
- when Qui-Gon shows Watto the hologram of the Queen's ship (even funnier if you could get Watto to respond with an "Aaaahhh, yes... rickroll")
Ep.2
- when Obi-Wan uses the library computer to locate Kamino
- when Dooku shows the hologram of the Death Star at the end