Apple - Safari is using too much RAM. How can I reduce its memory footprint?

So it appears that Flash is still the main culprit - if you enable any flash in ClickToFlash it stays resident in memory.

Following Gruber's advice on Daring Fireball, I've disabled Flash entirely on all browsers except Chrome and this seems to have helped immensely

This is just a fact of life using Safari. Spend some time browsing Flickr and it's memory usage will go way over a Gig. Gmail is another killer. I think Safari most be doing aggressive in memory caching to speed things up.

There's nothing wrong with turning off flash, but the main advantage is lower processor usage, not just memory consumption (though it's great to see turning it off has lowered Safari's footprint).

I don't think you need to worry about what Safari is doing with memory for a couple of reasons:

Safari 5 is a 64bit application, where as Firefox and Google Chrome are only 32bit (at least the mac public releases). This is relevant because 64bit applications appear to use more memory while they're running (The Growl team explains this better than I could, here).

If you've got free memory, which the OS (and Safari) can release quickly, safely and easily (speaking as a Programmer), why not use it to cache your web content - that's what it's there for. Trust your OS - it's clever, if another application needs the memory it'll just release the not-needed-right-now-bits-and-bobs.

Safari also has an unfair advantage- it's made by the same company that built your computer. I'm not saying Safari is infallible, or even that it's the best browser, just that you shouldn't over-think the statistics; memory is there to be used and if it's not negatively affecting your computing experience then don't stress.