Mount speed without being on mount!
FOUR SIMPLE STEPS:
1. Queue up on any scenario (tested in t3 elf/order)
2. Wait for the join window
3. Mount up
4. Press join JUST BEFORE you mount up (must be less than 1 sec when you get loading screen)
and there you go! You now have the 50% speed increase while not mounted.
You can also use all your skills and even flee (which gives 30% more speed!)
This effect lasts after you leave the scenario, but you cant mount up (duh!) since you already "are" mounted.