No 4. WordPress Database Backup

Probably the single most important plugin for WordPress; it allows you to backup your core WordPress database tables and other tables in one single database. The plugin is compatible with WordPress versions from 2.0.3 to 2.9.2.

Go here to download.

No 3.  WP Cache Users

Wonderfully useful if you run a multi-author blog; it cache’s individual author’s data so that only “that” author’s data is loaded whenever a post is viewed. This reduces the MySQL queries for plugins that “get_userdata”. The plugin has been tested for compatibility with WP upto 2.5.

Go here to download.