Something like the Firestorm Quick Preferences (button) pop up window to tick and untick the options in top menu Advanced - Rendering Types/Features options. This would be ideal to help people learn to control lag for themselves and in return reducing the amount of data transfers from SL servers as well depending on the infrastructure setup.

So people would be able to easily control what they want and not want to render/derender such as PBR, Sky, water, terrain, particles etc. On relog this should all be back to default or can also allow a setting to keep as default until reset. Many hangouts are in the sky boxes or buildings over waters and there is no need for the viewer to draw water particles like high latency/lag things. Many events where people are together lags everyone and most are having very low FPS putting a dent in enjoyment. Most people are not moving around, just chatting and camming on other avatars. At times like this turning off volume (CTRL ALT SHIFT 9) is a big help but 99.9999% people do not know about these shortcut keys. So why not have them easily accessible and let people learn to help themselves and this GRID. Plus with the future updates due + PBR atleast for some time till people catchup to better hardware and connections it will come extremely useful. Theses is a very easy addition as it is already there in the menus. Only need an easily accessible button for a quick pop up window.