EDIT: I moved the actual directory to my comment below, because this post wouldn't allow clickable links.
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)--
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://cofoundergoogledocs.com/
"Do you need a co-founder?" http://news.ycombinator.com/item?id=1052950
I'm actually not sure why there is interest in duplicating Google Doc spreadsheets. Either people forgot, or wasn't aware that there's already one :/