I've spent some time trying to figure out how to prevent Drupal from indexing some nodes. There are a couple PHP generated pages that don't seem to play nice when indexed.

Is it possible to prevent specific nodes from this or must I convert these nodes to a special content type and exclude them using search_config (http://drupal.org/project/search_config)

I'd much rather simply be able to detect when the page is being loaded for indexing and give it a teaser sort of thing. Example:

<?php if ($indexing): ?>
    Find and register for a class
<?php else: ?>
    Code here for class registration
<?php endif; ?>

Any ideas?