The Bluefire Blog has great advice on customising the output from your flash gallery by editing the style.xml located in the resources/styles folder inside your gallery. From the first post on this:
“The controls within the Web tab allow you to customize the Lightroom Flash Gallery templates in a lot of ways. However, you can customize them much further by editing the XML files that are generated when you export a gallery. This requires almost no knowledge of Flash or HTML, and can be done with almost any text editor.
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OK, tired of editing the XML files to further customize your Flash Gallery? There is an alternative – for style customizations at least. You can put the web tab of Lightroom into “advanced mode” when in a Flash Gallery template which will expose MANY more customization options in the Lightroom panels. See http://blog.bluefire.tv/ for info