Should I up my ram from 2 to 4 GB?

I am tempted by ... actually, the ads on this site, to upgrade my Macbook Pro's RAM to a whopping 4 gigs. I've always heard and believed and experienced that upgrading your ram always significantly improves performance, but just how much ram is overkill?

My situation:

I browse a lot, using both Safari and Firefox at the same time, as well as iChat, MSN Messenger, Adium, Word, Excel, VLC, Transmission and a number of widgets, all of which are usually open at the same time. Sometimes I want to use Photoshop during all of this, and often I want to run Windows XP in VMWare with in turn even more applications open in it doing all sorts of stuff. If I'm working on something (which isnt often) I might have many more programs and many more instances open, such as BBEdit, Netnewswire, CocoaMySQL, Paintbrush, along with both PS and VMWare.

I have iStat Pro on my screen at all times, and I notice that even when not running Photoshop or VMWare, my memory used seems to be around 60-90% at all times. This surprises me. What does Leopard do with all that ram? I don't see how these simple programs can use up so much RAM. I think Leopard itself already takes up a gig.

What will happen if I were to upgrade the ram to 4GB? Will the speed of my computer actually improve dramatically in every situation, or will it simply allow me to run more stuff at the same time? Will Leopard automatically use more RAM for itself because more is available, or will it still only use about 1GB?

Has anyone upgraded their memory to 4GB (specifically the low-latency one advertised) and can tell me about their experience?

Reading back my own post it seems like I need something in the area of 16GB to do all this, but I'm more interested in the improvement I will get when I'm not working on anything drastic, such as when I'm just word processing and browsing the web. 2GB is already a lot, will another 2GB actually do anything?

Upgrading your memory to 4 GB will certainly help and possibly add some speed to whatever you're doing. More memory is not an instant fix to turn your MBP into a speed demon but it's the least expensive way to gain performance from your machine. You might also consider upgrading your HD to a faster larger capacity drive.

Regards.

Will upgrading my harddrive void my warranty, or would I have to have an Apple center do it to keep my warranty?

According to Apple the MBP hard drive is not user replaceable because of its location and difficulty in removing. You would run the risk of voiding its warranty if you should change it yourself. Getting it done at the Apple store is best but it will be expensive.

Regards.

I've run 20 applications without hiccup. 4gb of ram is AWESOME!

Ge64 - I just upgraded my RAM yesterday on My MacBook Pro 2.4Ghz from 2Gb to 4Gb and It made a HUGE difference in how much stuff I can have open at the same time. I use Istat Pro to watch over HD and RAM usage and I can definitely see the difference in speed and amout of apps i can open all together. I just purchased my RAM Kingston 4GB Kit (Apple Specific for MacBook Pro) at Newegg.com for $74 plus $6 shipping.