Old News
Well, I got fed up with the idea of paying lots of money for a yarn swift ($70!), so I decided to make my own.

Basically, it's a device used to help unwind skeins of yarn; they're sold in large coils, and most useful (and portable) in balls. For some reason, I was willing to plunk down the cash for a ball winder, but not an umbrella swift, both depicted here:

Commercial Ball Winder and Swift
So, in typical fashion, I decided I'd make my own, and it turned out like this:
Finished Swift
As you can see, it's a different design. Rather than have an expanding frame, my swift has moveable pegs that fit into a rotating dowel. Construction was fairly simple; the hardest part was getting the axle & wood with the hole for the axle attached to a clamp so the whole device could be affixed to a table.

I modified a store-bought spring clamp with an extra piece of aluminum:


Modified Clamp

This small plate ensures that the upper arm of the clamp is always parallel to the table-top (if there were no plate, there would be some play in the clamp). Luckily, when I pulled off the bright orange handle, there was a hole, pre-drilled for easy mounting.

I drilled a series of holes in a large dowel

Drilled Dowel
as well as a thru hole in the middle for the axle
Drilled Holes
After gluing some dowels together to make the adjustable pins and gluing the axle in place, I had a finished product:
Finished Swift
Here it is in action:
Finished Swift with Yarn