Werysoft, Inc has made some pretty impressive tools to use with PowerBuilder, that really brings the functionality up to a more modern look. Things like an Outlook navigation panel, dockable controls, toolbars, menu ribbons, headers, tab controls, etc. Check it out on their site: http://powertothebuilder.com/
We have been using several of the items for around 4 years now, and have been VERY happy with their performance.