Just a quick tip for what seems to be a common problem. It looks like the issue is a simple memory limit requirement. link to original tip

What I did to get things working:

1. Installed fresh copy of MAMP
2. Grabbed fresh copy of Drupal
3. Moved it to the right folder, usually /Applications/MAMP/htdocs/
4. Unzipped it with Apples BOMArchive Utility (NOT Stuff it), I don't know if it makes I difference, but I hear it preserves hidden files/permissions better then Stuffit
5. Went to the /sites/default/settings.php file, enabled read/write permissions for everyone
6. Added the line: memory_limit = 12M to my php.ini file in my MAMP/conf/php5 folder (I'm running PHP5)
7. Added the line: ini_set('memory_limit', '12M'); to my drupal settings.php file
8. Added the line: php_value memory_limit 12M to my .htaccess file in the root Drupal folder.
9. Ran localhost:8888/drupaltest/install.php and it worked like a charm.

So far running Drupal on a MAMP install with Apache 2, and PHP5 makes for a much faster and more responsive experience, much improved over the default apache 1.2/php4 combo you get by default with OS X 10.4