Firefox

How much memory does Firefox take up just surfing a forum? On average.
 I was just in /g/ and i noticed firefox took up 160,000k. WTF? It was only that, and nothing else in the background. Is it because I have 1.5.0.11? Which I doubt.

It's because you're refreshing and it keeps things in cache. Just restart it.

or google changing the cache size settings.  mine never goes above 75,000k now

Firefox caches previous pages and whatever media they contained in your hard drive _and_ RAM which doesn't make that much sense on an imageboard since the content doesn't stay the same for very long. Try disabling the memory cache through about:config.