SelfControl 1.2.2 for OSX -- block yr email, facebook, twitter for blocks of time, but still access rest of web: http://bit.ly/emqeW
Is email a distraction? SelfControl is an OS X application which blocks access to incoming and/or outgoing mail servers and websites for a predetermined period of time. For example, you could block access to your email, facebook, and twitter for 90 minutes, but still have access to the rest of the web. Once started, it can not be undone by the application, by deleting the application, or by restarting the computer – you must wait for the timer to run out.

Just got to 600 documents in my Yep library. Still one of my favorite pieces of software ever. http://bit.ly/s2TQG

tjw: Another option, if you like OmniOutliner for writing, is @fetjuel's OOhelpify http://j.mp/2f0EtQ

Snow Leopard compatible ANSI color changer for Terminal.app available @ http://niw.at/articles/2007/11/02/TerminalColoreopard/en

I haven't used this yet, but it looks like my favorite user feature in SnowDacted. http://support.apple.com/kb/HT3774

Great video from @boagworld: perspectives & contexts, capturing actions from paper... 17mins, all great tips! http://tinyurl.com/mkykmm

Skim is a v. good pdf reader/annotator for the macking tosh: http://j.mp/wDkd