Here are personal success stories detailing the use of CruiseControl in the [RealWorld].

CruiseControlAtSas

"We've just moved all the Java code under CruiseControl. That's (approximately) five million lines of code and we are running on a single CPU box."

CruiseControlAtLandmarkGraphics
We're building 25 different projects, with various interdependencies, in 3 different cities. It is a mix of Java, C, C++, and Fortran, built for 3 different OS's.

Automatically testing/applying patches on top of Continuous Integration, a setup combing quilt and CruiseControl.
See also MocaPublicCCInstallation.