Purchase this tool (for free!) on the Second Life Marketplace:
> Get Slide Toggler <
This is a single LSL script which you can use when presenting slides of information in Second Life. First, create each slide as a flattened box (or any other shape you like), with the front facing on its local +X axis. Next, put this script into each slide. You can then click each slide to toggle it to the foreground or background, and (as of version 1.2) optionally have an auto-reset timer which makes slides go back to background after a set period of time.
Foreground slides are full-bright and enlarged, while background slides are semi-transparent and at their original size. You can customize everything reasonably easily by changing variables at the top of the script, including who has access to control the slides.
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