Scroll of Recall

If you are over level 40, it just dumps you into a random location somewhere in the world with a 20 minute cool down. Due to this, it has limited usefulness, but quite a bit of entertainment value!

So far, I have been dropped:

1. 
   
2. In the arena inside Gadgetstan
3. 
   
4. On a parapet outside Booty Bay that I didn't know was reachable
5. 
   
6. On a hill overlooking Auberdine
7. 
   
8. Just outside Aerie Peak in the Hinterlands
9. 
   High in the air above Swamp of Sorrows (it seems some of the locations are common as Xymox said below)
   

I'm unsure if the locations are faction specific, but so far it hasn't dropped me into any Horde towns =P

Like iamjake said these are mostly for entertainment value.

I have been teleported to tanaris areana twice, stonard once, and i was dumped in the air in swamp of sorrows and fell to my death next to a guy fishin on the beach. that was really funny. There he was just relaxing on the beach with his fishing pole. Suddenly, a dead Tauren hits the ground next to him. He was like WTF? we had a good laugh over that one.

In that beta build, they worked for any level. In build 8926 they were changed to level 50 and lower. Now in beta build 8962 they're unpredictable above level 40. 1st Test in beta 8962: My level 72 shadowpriest standing in Ironforge with a hearth set to Dalaran used a Scroll of Recall. I got teleported to Auberdine and gained the debuff "Lost!: Too high level to use Scroll of Recall and was teleported somewhere at random." 2nd Test: Hearth set to Dalaran and I got teleported to Aerie Peak in the Hinterlands. Got the "Lost!" debuff again which lasts for 60 seconds.