I also need a "HTML TextArea" box and played around with input w/multiple lines activated. The problem is that when the user writes more than there is room for, then things turns ugly.
Some solutions to tackle this problem:
1. Some hacking of UITextList so it would work on an input field. I tried this without success.
2. Some hacking of UIDraggablePanel & UIScrollBar to make some kind of scroll view. I tried something, but quickly found out this was hard.
3. Limit the input to x characters. This is the only solution I found so far. It sux, but at least it doesn't look ugly.
So I guess this is kind of a request, or a cry for help if you see a way for me to make a proper TextArea box.