Mac's OS RAM memory usage / consumption

I'm a recent switcher and I'm trying to get a good understanding of the Mac's OS RAM memory usage / consumption.

I have a 2007 Aluminum iMac, 2.4 Ghz, 24 inch screen, 500 Gig HDD, 2 Gigs RAM. Looking at the Activity Monitor or iStat, I can see that I have about:

200-230 Megs or Wired memory
500+ Megs of Active memory
500+ Megs of Inactive memory
700+ Megs of free memory

all out of a total of 2 Gigs

These numbers are without any programs running besides the Finder, Quicksilver and a few of the basic Widgets. The computer's been running for over a week without a restart (I put it into sleep mode instead). Is this normal to have this much Active memory? I think I've read that certain programs can take more and more Active memory as the computer goes without a restart but I'm not sure how true that is.

Anyone have any insight on this or know where I can get more info?

I think having that much active memory is totally possible. And yeah some apps do make more and more of it active. But beware for some apps have a memory leak and make this even worse.

I think a quick log off and back on every so often would fix this problem I think and is lex tasing on the machine than a full restart.

It's normal. If you hover the mouse over the labels next to each it'll tell you what they mean. I'm not sure of the difference between Inactive and Free - I think Inactive is memory that has been used in the past and then deallocated, Free is memory that's never been used.

I just found this article. It should answer your questions.

http://docs.info.apple.com/article.html?artnum=107918

Thanks for all the help!