I got one of those tiny tripods as part of my quest to solve this problem, and I felt a bit nervous putting my Sigma EF-530 DG or Metz 48 AF-1 flash on it. They're really designed for compact cameras, and a big vertical flash has a much higher center of balance. I ended up making a foot myself from a small block of wood, a metal "cold shoe" clip with a screw hole, and some electrical tape.
But based on a little poking around I did last night, I think this is the answer, for $8:
Nikon | AS-19 Speedlight Stand | 4763 | B&H Photo Video
And unlike the twice (or 3×, with shipping) as expensive Pentax version, it has a tripod socket. Nice.
Although if you happen to be in Japan with an extra ¥6500, check out the
Pentax CL-10 Off-Camera Flash Clip, which looks
awesome.