That's a bold-faced lie.
Over-clocking is doing just that... a processor (RAM is considered a processing unit to me) is set to have X hertz of power go through it. Like, for instance, it's CLOCKED at 2.66 GHz (My Processor is, at least). When you -clock, you either set that value higher, or lower. Setting it lower slows the PC by throttling the frequency of power that's being sent through the processor at a given time, while over-clocking it raises the frequency of power increasing the output. Although, it's usually really stable if done with in reasonable limits. Some RAM is now built to be over-clocked, while processors have been over-clocked for YEARS.
Over-clocking RAM is dangerous because RAM is really finicky and if you mess up, kiss your RAM goodbye... and the increased output is usually only measured in milliseconds, and does have stability issues.
But that can't be said about all over-clocking. My GPU (Graphics card) is over-clocked, my processor is over-clocked, and it ran flawlessly.
You just have to remember limits. Try it in increments of .05-.1 hertz at a time... and I think RAM is clocked in Mhz. So increments of 50 or so Mhz.
And 2GB should be fine for nearly any user. I have 2 GB of Patriot, a 2.67 Ghz C2D (e8200) and a 9800 GTX OC'd to 780 Mhz IIRC, and I can run any game at full settings with AT LEAST 35 FPS.