Google Charts can get pretty interesting. I haven't gotten to anything dynamic yet (buttons to filter), but created a portlet to display customers' YTD vs Last YTD for our Outside Reps. Gives them a nice comparison of where their customers are compared to last year, which also allows sorting by $ +/- change. Even includes links for the reps to easily view their Open SOs and Open Quotes. I think it's about 4 or 5 saved searches displayed in a nice clean portlet. Only downside with Google Charts is you need someone to build it all out.