Re: Lowering RAM Use
I don't think your RAM is much of a problem. I'm using full Ubuntu with 7 tabs open in Chromium, and using 412 megabytes of RAM.
An older computer with 512mb of RAM probably has an older, slower CPU and GPU. What are the exact specifications of the computer? Really, anything based on Ubuntu is not going to be very lightweight and if this really is an old computer it might be better off with a real lightweight Linux distro.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.