Update: Please update your theme to version 1.9 – this tutorial isn’t required anymore…
This tutorial will guide you through all steps which are necessary to use the “Media Gallery” in combination with Flashlight.
You need to download the Flashlight theme. I’d recommend the latest version from Themeforest.
Afterwards download the “Attachments” Plugin from the offical Plugin Repsitory. The direct link is: http://wordpress.org/extend/plugins/attachments/. You can buy the “Pro” version but it’s not necessary. The free version offers all features we need right now. If you’re developer the pro version might interest you though.