This might be a silly question.
How do I run an application with an Instrument in XCode 4 such as Leaks?
I do not see the option like I have in the past, and
Click and hold on the run button, and choose the profile option.
You can also edit the profile scheme to make it use debug builds when profiling. To do this, go to edit scheme by click on the dropdown next to the stop button:
Then select profile item on the sidebar, then make sure 'Build configuration' is set to debug.
as jeff said, that is 1 way you could do it.. other way with keyboard shortcuts is press cmd + I and this runs the profiler and after that you can choose leaks...