Hacker News Reader

Highly relevant if you're interested in learning these, or are bad about remember all the random keys in disparate apps is CheatSheet: http://www.cheatsheetapp.com/CheatSheet/

Pop up that shows available keyboard shorcuts (activated by a keyboard shortcut of course :)

View on HN

I tried that out a month or two ago, and liked it but quickly removed it. At the time it was popping up its sheet when you invoked the command-tab switcher, which was really annoying.

They seem to have fixed it since then.

Reply on news.ycombinator.com