I had never heard of magic loop until the current issue of Knitty and found a wonderful how-to video at KH, of course!
I think I know the answer to this already, but thought it better to ask. Let's say you've got a sweater pattern that calls for US 7 circular needles in both 29" and 16" lengths, the 16" being for the collar. In the pattern, where it tells you to switch to the shorter circular, could you instead switch to magic loop? I'm dying to make the dog a sweater, but I can't stand buying circular needles in 500 sizes when I already them in some sizes when I could be spending the money on expanding my Turbo collection, a much-needed S.E.X., or saving up for the Jordana Paige messenger bag, which totally has me plotzing already.