I've rewritten some functionality, so it's nicer to me now.
I've upgraded from only using PermissionsEx system, to using the default Bukkit API. This means you're not bound to PermissionsEx anymore!
There's been changes to the config.yml located in the plugins/LightWeightWhitelist folder, so if you've used the plugin before, remember to delete the folder (LightWeightWhitelist) and restart/reload your server.
Together with organising the config values, I've also added a debug option. This will only log a bit more information to your server so you can easily find out if you've done something wrong with your permissions file (like forgetting to add lww.whitelisted to the groups/players you wish having whitelisted).