For knitting hats in the round (which I prefer cause there's no seam to sew!), 16 inch circulars are usually what are called for. To me it's easier because you just knit around and around verses having to switch needles like DPNs. It's all in preference. If you use the 16 inch actually you'll need DPNs for when the number of stitches with the crown decrease gets too small to fit on the circulars.
You can also do hats with magic loop, which wouldn't require you to switch to DPNs later.
You can try different methods and find the one that works for you :D
Last edited by thepurplegg : 03-14-2009 at 06:10 PM.