I use [MacVim](http://code.google.com/p/macvim/) as my editor and [Dash](http://kapeli.com/dash) as my documentation browser. They’re great. Also, Dash has the best nag-screen mechanism I’ve ever seen.
If you use them, too, I wrote a bit of Vim script to make looking things up about 0.5 seconds faster each time. Imagine, _all that productivity!_ Just position your cursor on the word you want to look up, leader-d, and the script will try to search the right docset in Dash based on the filetype you’re editing. E.g. for JavaScript files, I have it configured to launch js:term in Dash, which searches both the jQuery and JavaScript docs for that term. (Source: a great tip from [Kapeli](https://twitter.com/kapeli/statuses/239927573096837123) himself. Herself? Itself?)
I’d love to hear suggestions on how to generalise this, without manually adding docsets each time. I tried passing in the filetype to Dash as the search term, but got tripped up by some asset files in Rails that Vim thought were ERB…