One of the things that used to drive me crazy with PerformancePoint was that I could only fit two drop down parameters on the top of a dashboard. I finally found this post that explains how to adjust it. It works great. Then tonight, I was trying to do it again and I had to search forever for it, so here it is. Preserved forever.
If you need to change the width of the parameter drop downs in PerformancePoint Server 2007, check out this link.
http://blogs.msdn.com/performancepoint/archive/2007/12/18/working-with-the-monitoring-css-files-to-adjust-settings-in-deployed-dashboards.aspx