Once I'd run my unit tests, I browsed to the Apex Classes setup page and found a new column in the class list which is going to save me time on every project I work on - code coverage:
During the development phase of a project, the first thing I do every morning is run all unit tests and check the output to see if I'm missing any coverage. If there's been a lot of development taking place, I'll repeat this many times during the course of a day. Sometimes I'll scribble the names of classes that need attention or print out the results page, but it all feels a bit clunky. Now all I need to do is to execute the tests once (which can be automated - there's a post explaining this in the pipeline) and browse to the Apex Classes page each time I want to see the coverage percentages.
Even better - this looks to be available outside of the pilot program functionality - I've just checked my free force sandbox that has been upgraded to the Spring 11 release and the code coverage figures are there!