Scala: how can I sort an array of tuples by their second element?

In scala 2.8, there is a method sortBy. Here is a simple use case:

scala> val arr = Array(("One",1),("Two",2),("Four",4),("Three",3))
arr: Array[(java.lang.String, Int)] = Array((One,1), (Two,2), (Four,4), (Three,3))

scala> arr.sortBy(_._2)
res0: Array[(java.lang.String, Int)] = Array((One,1), (Two,2), (Three,3), (Four,4))

scala>