Man, I just enchanted the most AWESOME sword! Sharpness II, Knockback II, AND Fire Aspect II! And for only 20 levels, too! Win!

EDIT: And for 19 I got Efficiency II, Unbreaking II, and Fortune I! And that Fortune I?
Gave me over a stack and three quarters glowstone dust from just TWO formations (and relatively small ones at that)!
My grinder is consistently gaining me 10 or so levels every 30 seconds, provided I wait a few minutes to start. Yeah-uh!
Splash Potions of Health hurt undead enemies, so you can use that to wipe out the contents of your grinder easily.
-Canama
Do Weakness potions work on Blaze? Because if not, it's gonna be a while before I can brew anything else; I don't have access to Nether Wart until I can close off my Blaze spawner. (I don't want to destroy it for obvious reasons, but I can't take a step outside my protected hallway without getting jumped by Blaze. Then the ghasts show up...) I'll have to enchant some fire protection armor if not, which means a few more iron swords' worth of zombies...