Why did Elisha curse children? 2 Kings 2:23-24 (KJV)
  23 And he [Elisha] went up from thence unto Bethel: and as he was going
  up by the way, there came forth little children out of the city, and
  mocked him, and said unto him, Go up, thou bald head; go up, thou bald
  head.  24 And he turned back, and looked on them, and cursed them in
  the name of the LORD. And there came forth two she bears out of the
  wood, and tare forty and two children of them. 


What do these verses mean? What was the purpose of this?  The only reason I can think of is to teach the severity of mocking God's anointed.
First, the term "children" is a poor translation in the KJV.  It's better rendered "youths" (as in the NKJV), which really changes the meaning of the story.

Imagine being accosted by more than 40 teens at once, intent on making trouble for you, outside of town.  This was no simple mocking; Elisha's life could very well have been in danger, and there's no indication that he was a warrior.  So instead, he followed his Master's example.  If they were taunting him and telling him to "go up" (ascend to heaven as Elijah had,) then he would have the Lord fight for him, as Elijah had in his confrontation with the priests of Baal.