I forgot to mention that on Friday night I visited the newly opened Posh: A Yarn Boutique. Cute little store! (But I have to gripe about the website's claim that it's "Colorado's favorite yarn shop." C'mon, the place is brand-new!)
It didn't yet have in stock the things I needed just then (reinforcing thread, more dpns) but did have something I wanted, namely, more sock yarn: Skacel Trampoline Stretch No. 238. It's brighter and more jewel-like than this photo shows.