JScrollPane and JList auto scroll

When adding a new message, invoke scrollRectToVisible() on the JList using a Rectangle having the same dimensions as your message pane's preferred size. Given a vertical orientation, it may be convenient to make the preferred size of the JScrollPane's JViewport an integral multiple of the message pane's height. See also: How to Use Scroll Panes.

Addendum: This compelling discussion of Text Area Scrolling may be helpful, too.

this.list = blah blah... 
this.list.setSelectedValue(whatever);   
final JScrollPane sp = new JScrollPane(this.list); // needs to be after the parent is the sp 
this.list.ensureIndexIsVisible(this.list.getSelectedIndex());

I found this really useful: http://forums.sun.com/thread.jspa?threadID=623669 (post by 'inopia')
It works perfectly

As he says: "The problem here is that it can become a bit difficult to find an event that fires after both the ListModel, JList and JScrollPane have been updated."