How to get by insufficient memory impass - can't access site?
There is 3 method to increase your PHP memory limit.  They are all outline in http://drupal.org/node/207036 

The best way to check your current situation is to create a file in the root directory call phpinfo.php, with these lines of code

&lt;?php
  print phpinfo();
?&gt;


Then check the settings by going to http://www.example.com/phpinfo.php