Array behaviour works with textareas as well. Enter three reasons:

I have some default text in the body of the tag


It also works with select boxes. Choose your three favourite animals:
<% ArrayList things = new ArrayList(); things.add("cats"); things.add("dogs"); things.add("rabbits"); things.add("horses"); things.add("donkeys"); %>

Note that select boxes with multiple=true do not participate in the array scheme. So this select will show all of the selections made for "fav".