We first took a look at Koush's ClockworkMod Superuser app about a week ago, and we were impressed with what we saw. A well designed utility app for rooted users, that brought a great feature set along with being free and open-sourced. At the time, the only way to try it out was to flash it manually, either via ROM Manager or via recovery.
That all changes today as Superuser has been pushed to the Google Play Store to download and install to your device. Also since the beta builds, some 'embarrassing spelling mistakes' have been rectified, as well as a few other fixes. It will remove any current Superuser apps on your device, and if you're having issues installing via the Play Store, links are provided in the description to a direct download to flash manually.