You can knit flat on circulars (and in fact I have yet to use any of my circular needles to work a project in the round). Just knit across your row like you would with straight needles, then turn your work, and knit back across the row.I never could get the hang of using circular needles, probably because I need to have enough stitches to begin with so it can slide easily around (never thought of looping out the excess cord).
The skewers obviously did not work very well, but when all you want is to keep a kid entertained until she's bored again, it worked.
I bought this brand of interchangables and never looked back. The red cords are a dream, but I'm not a fan of nylon cables anyway. The bamboo needles and the steel needles both work with the same cables, so I can swap back and forth as desired based on the yarn and how much friction I need, although I'm mainly working on the steel tips nowadays.