IPhone: Should I use 'instruments' to verify memory leaks?-Collection of common programming errors

No.

But at least run “Build & Analyze” in the XCode. It tells you what it can find about the memory leaks, just by analyzing the source code statically. It’s basically eye-balling the code by the machine. It’s infinitely better than doing that yourself. If there’re any warnings issued, fix all of them. It’s rare for the static analyzer to give false positives.

Also, running your app with Instruments is helpful to see how it really allocates memories. Sometimes it’s fun, too.