A great little tip for Firefox users. With these instructions, it limits the ram usage to less than 10MB whenever you minimize Firefox.
Just follow the instructions:
1. Open Firefox and go to the Address Bar. Type in about:config and then press Enter.
2. Right Click in the page and select New -> Boolean.
3. In the box that pops up enter config.trim_on_minimize. Press Enter.
4. Now select True and then press Enter.
5. Restart Firefox.