Nothing like sitting down to start a (hopefully) productive programming session to find your local servers ala MAMP Pro won’t fire up after last night’s upgrade to Mountain Lion.
The Internet says it’s a port issue.
This post on tweaking your port seemed to work for many, but didn’t on my end.
Other’s suggested sudo apachectl stop to stop the operating system’s instance of Apache, but that didn’t work either.
What finally worked on my end was upgrading to the latest MAMP (2.1.1) which is listed as compatible with Mountain Lion.