The red-and-white hairnet that I've been working on is finished apart from the last finishing touches. I put in the last knots during Freienfels, and I started another one right away - same mesh size, but thinner thread. The plan is to put pearls in the mesh of the new net.

First of all, here's the photo of the finished piece. It turned out with a diameter of a little more than 30 centimetres when laid out flat on a surface, and it took 29 and 3/4 hours to get it to this stage, net working time since I work with a stopwatch. (I miscalculated during the weekend and told people a larger amount of time. I'm not happy about that, since I like to get my numbers right, but I'm still content that I erred on the side of longer work time. And everybody watching could see how long it takes to make the mesh...)
It is still lacking a band that will be attached to the mesh in front of the net and drawn through the longer loops on the back of the net - this allows some width adjustment when wearing the piece. It also still needs the finishing touches: a proper crown closure with silk thread (there's still the pink cotton thread in it that I used as a foundation loop), snipping off the rest of ends, and wetting it down to dry set over a bowl or something similar almost-head-shaped.

On this closeup, you can see the colour change between red and white, marring the impression that the net is worked in the round.

I'd say that an unadorned, simple net might well be worked in a spiral, since it will take very hard looking to see that: In the crown section, there's too much thread on too small an area, and the lower end of the net, if stitched to a band or sporting longer loops for closure, will not be easy to read. For any net that will show different size mesh, colour changes or embroidered patterns, spirals are out of the game, because they are just irregular enough to show. And according to my experience, netting in the round will not take much longer - there's only one slightly more fiddly point once each round where you transition into the next row; compared to the amount of time needed to complete the round, the slight slow-down there is not even worth mentioning.

Edit Jan 21, 2010: This is not correct - there is evidence that nets with colour changes and different size mesh and what-have-you were also netted in a continuous spiral. Please see update here.