Missing memory?

Hey all,

I'm originally from the PC world and used to know everything about my PC, but I decided it's time to expand to the Mac world. So far, I'm loving it, except when I run out of memory...

My Mac has 1 gb of RAM, but yet it seems to vanish quickly. Not sure exactly what's doing it, but when I go to the Activity Monitor, the kernel takes up most real memory (about 60-70 mb, sounds reasonable?) Freashly booting, I have around 400-500 mb free, but once I start doing stuff, the memory drops... and even when I quit my programs, the memory doesn't recover. In fact, I just added up my memory according to the activity monitor, and it seems to be about 500 mb used by applications, with about 100 mb free, so where's the other 400? I'm guessing around 100 mb is in the shared memory, but where's the rest?

I guess a better thing to ask is how can I reliably determine what applications are hogging all my real memory? I don't really like using the swap space, since it slows down my computer... Also, what changes can I make to increase the amount of free memory?

In case it helps, here's a list of applications I have installed, above the stuff included with my Mac:

-Adium
-Adium Book
-Firefox
-Flip4Mac
-Gizmo Project
-Growl
-JAlbum
-Logitech keyboard software
-Microsoft Remote Desktop Connection
-NeoOffice
-Onyx
-Palm Desktop
-PySol
-QuickSilver
-Skype
-Smultron
-Solitaire XL
-StuffIt 10.0
-Synergy
-TeamSpeex
-TinkerTool System (no changes made)
-VLC
-World of Warcraft

Dashboard Clients:
-miniFreeRAM
-Canada411
-CurrencyConverter
-Chi Pet
-StatCounter
-Swap Usage
-iCrono
-miniCPUUsage

Thanks for any help you can provide

To be honest, I wouldn't worry so much about it.

OS X tends to reserve a lot of excess memory for applications and files, even if it doesn't actually need it.
But if you actually need additional RAM to run applications, it should give re-distrubute it accordingly.

So unless you are noticing massive RAM-related slowdown, let the system do its thang

(Things to look out for: Widgets hog a fair amount of memory, so do any running applications that are running through Rosetta - update them to Universal binaries where possible).

P.S. Case in point: I have 1,25gigs of RAM and I'm currently running Safari, iTunes, Mail and Transmit and around 8 widgets and I only have 17MB free RAM.