In a Drupal site you may have a content type that needs an auto number to be generated that auto increments on each new node of that type.

To do this install the computed field module

http://drupal.org/project/computed_field

Then create a new field of the type computed field and add the code from the following URL

http://drupal.org/node/313110

If you need to display a random image from a folder on your website then this tutorial may be of use

http://www.reconn.us/random_file.html

It’s very easy to follow and you can set it up in minutes.

If you get out of memory errors in PHP or if Drupal suggests you increase the memory available to PHP then you can do this with the following line of code:

ini_set('memory_limit','16M');

In Drupal the best place to put this is in the settings.php file found in sites/default/