I keep getting déjà vu every time a new HN directory appears, so I tracked down all the ones I could remember. I'm sure I've probably missed some...
EDIT: I moved the actual directory to my comment below, because this post wouldn't allow clickable links.
http://hndir.com/
HN Post: http://news.ycombinator.com/item?id=801496
--HN Contractors--
https://spreadsheets2.google.com/ccc?key=tk7rUIb-2aPdk_5gFJE...
HN Post: http://news.ycombinator.com/item?id=1262467
--HN Hackers (inspired by HN Contractors)--
http://hnhackers.com/
HN Post: http://news.ycombinator.com/item?id=1264544
---HN Proxy Desk Neighbor List (aka HN Yellow Pages)--
http://spreadsheets.google.com/ccc?key=tFgepUuuBHSgfeuKPKccx...
HN Post: http://news.ycombinator.com/item?id=1517198
--HN Yellow Pages V2 (uses form, not directly editable)--
Form: http://spreadsheets.google.com/viewform?hl=en&formkey=dE...
Spreadsheet: http://spreadsheets1.google.com/ccc?key=tJ4MdE7OPPucXtJAAKda...
HN Post: http://news.ycombinator.com/item?id=1517430
--HackerNewsers (search by skill and location, inspired by HN Yellow Pages)--
http://www.hackernewsers.com/
HN Post: http://news.ycombinator.com/item?id=1520916