This plugin is awesome! It's called Cobalt WP Boost, and you can get it here: http://frugaltheme.com/about/cobalt-wp-boost-plugin/ As someone who runs a lot of big plugins on my site, and with the release of WordPress 3.0 right around the corner, this thing couldn't have come along at a better time! It allows you to monitor memory usage on your site as well as bump the default limit of 32MB up to 64MB or 128MB with just a couple mouseclicks!