If you are running Drupal websites locally on your computer using the MAMP / MAMP Pro stack and are experiencing abnormally slow page loads, there are a couple of steps that should be taken to help increase performance.
The obvious approaches are to check your php.ini settings and insure that your allocated PHP memory is sufficient to your local needs. Additionally, making sure that my.cnf has been configured to support database loads and performance is also a must, however MAMP does a fairly good job of giving you what you need out of the box.
If you've taken these necessary steps and are still experiencing slow load times, you may want to consider enabling APC caching on your MAMP stack. To do this, simply launch your MAMP application. Insure that the "Server" tab has been selected in the top left and click on the PHP sub tab. In the bottom left, you'll see a section labeled "PHP Extensions, with a drop down under the "Cache" label.
Simply select APC and restart your APACHE / MYSQL process. All done! Ultimately your local environment is going to be subject to the performance that your local machine can output, but enabling a solid caching system like APC should give you the noticeable boost in performance that you have been lacking.