I remember there was someone here who was kinda afraid of circular needles. Before I say this, let me say that there is nothing to be afraid of. Really, there's not even anything to learn, especially for just knitting flat on 2 circs. Just treat them like two straights that happen to be connected by a cord.
BUT, if you are really intimidated by circulars, seeing the cords attached to the Knitpicks options needles with the cap screwed on one end as a stop in the Knitpicks catalog I just got showed me you can make extra long flexible "straights" where most of the weight of the work will lie in your lap.
So for the person who wanted to knit an afghan on straights, order the size tips you need for KnitPicks Options and a set of long cables, and put the little screw caps on one end of the cable, and there you have it, a flexible pair of 60 inch "straight" needles.