When Fast Traveling in Playthrough 2, you will notice that most areas are unlocked from the start. This can be very helpful to speed your way to later areas. For instance once the Vault was ready to be encountered, I simply fast-traveled right to the end-boss, instead of trekking through multiple areas and enemies. There was also a neat glitch when I did this. The cinematic had a gun reticle enabled, and I could switch weapons and shoot invisible bullets at the center of the screen. Useless...