Never think too hard about your bags again!
This plugin replaces your inventory with it's own categorified inventory addon.
1 image from the plugin's author. Click one to see it full size.
/xlsettings, open the Experimental tab, and turn on Get plugin testing builds. This plugin is only released as a testing build, so it won't show up in the installer until that setting is on./xlplugins to open the plugin installer.