before :all trick that we use to good effect in a lot of places. https://github.com/psyho/fast_context
talk about a little bit more in fast-tests-drive-toward-clean-architecture
At the bottom of this page is a plea against using them like this: http://old.rspec.info/documentation/before_and_after.html
talked about the same before :all trick that we use to good effect in a lot of places and gave it the name "fast contexts".
The Thoughbot guys talk about a similar technique they use in their acceptance tests in podcast-bike-shed-episode-1, but that might actually be something slightly different. That's more about getting an acceptance test into the heart of the application, then running multiple tests there so you don't have to re-run through authentication every time. Not sure if it should have the "fast contexts" name or not, since they didn't explicitly call it that.
Used more in testing-concept-long-lasting-regression-tests than when initially doing early stage testing. See testing-concept-stages-of-testing.
Depending on how loose the definition of fast contexts is, it might also mean more than just before (what did I mean by this?)