How can I tweak vocal recordings in my audio software (GarageBand/Soundbooth) to have that soft synth effect that Kevin Rudolf has applied in Shooting Star LMFAO remix?

Just saw a question about orphaned questions, decided to look over them, and saw this! Don’t know if the question is still pertinent, but anyways…

It would help if you post a clip of what you’re looking for since I’m not familiar with the song, but I’m guessing you’re probably going to use the flanger. For something soft and warm you’ll want to make your signals the same polarity. (If you’re looking for something a little more metallic you’ll want to get them opposite in polarity.)