Markus really liked the NU-XTAL quartz crystal breakout board, so he decided to build his own. He had one of our QFP protoboards laying around which had a small quartz crystal breakout on them. He cut it out, hot-glued, and soldered the pins.
I like your idea of a plug-and-play XTAL solution for breadboarding. I had to use some XTAL to get USB communication working with a PIC32. (It won’t enumerate using the built-in RC oscillator.) Until I saw your post, I had a fearsome XTAL and SMD-capatcitor air-wire construction on my breadboard.