I'm considering upgrading the RAM on my Dell 9300(currently 512MB) to either 1GB or 2GB. I'm not sure I want to spend the $200 on 2GBs, but if upgrading to 1GB will definitely be noticeable I'll may just upgrade.
My CPU is a Pentium M 1.73Mhz.
I mainly use my laptop for surfing and burning CD/DVDs....so I'm not sure the upgrade would be worth it.

My laptop has 2 slot for RAM....is it okay to have a 1GB chip and a 256MG chip or do I have to buy a matched set?

Going from 512 to 1gig is a noticeable difference. I did it with mine and it's a lot faster. I also did it with my laptop and it's faster too. I've heard that going to 2gig is not as noticeable, but I would not know for sure. I would recomend just adding another good name 512ram to your computer. As for your laptop, I'm not very knowledgeable about those. I've read where people have had trouble when they left the old (256) or whatever in with the new ram. I replaced 2-256 chips with 2-512 chips in mine.

Hope this helps, I'm sure somebody else will come along with more info.

Where's the cheapest place to get RAM? Is one brand name better than another?

I get mine from www.newegg.com, you can go to www.crucial.com and they have a question thingy that will tell you the correct type of ram for your computer. Some good brands of ram are Crucial, Kingston, I've got some brand..IPQ or something like that and so far had no problems. There are consumer ratings at newegg you might want to read up on some.

From Crucial's site:

"Although the memory can be installed one module at a time, the best performance comes from using matched pairs of modules."

Crucial's page for your memory
Mark

You can always sell your old RAM on Ebay or Craig's List and make a few bucks

Unless your playing the latest and greatest games out, you probably won't notice much improvement with more then 1gb of ram. I had 512mb of ram and upgrade to 1gb recently and its a noticeable difference! Everything opens up faster, even my computer turns on faster.

You need to make sure that your motherboard in your laptop can actually use 1gb of ram. Not all computers support 1gb, and some older machines (motherboards rather) might only support 512mb of ram. Just because it has 2 slots doesn't mean you can stuff a stick of 512mb in each....if it'll only recognize 512mb of ram and you put in 1gb, the computer will only use 512mb. Some mother boards will also only recognize certain sized modules (sticks of ram) and might not recognize a single 512 or 1gb stick.

Also, you'll have to check whether or not your motherboard uses sdram or ddram. The main difference (aside from speed) is that ddram (Double Data ram) runs faster in pairs, while sdram (Single Data ram) doesn't matter if it's a single stick or a pair or 57 sticks or ram, it's still single data.

You can use SIW (System Information for Windows) to figure all this out. Click on "Motherboard" to see the details of your motherboard, paying special attention to the "Memory summary" section.

Hope this helps!

max RAM is 2BG on my dell. The reason I ask about mixing RAM is because I can get a single 1GB ram stick for the same price as a pair of 512MBs. Which would run faster(better)....a pair of 512s or a 1GB and 512mb?

It will run with either configuration. However, I've always been told that they run faster when matched, so I should think that 2 512's would yeild a better performance.

You could also get a 1gb stick now, run it at 1.5gb of ram, and save up for another 1gb stick to install in a few months (or whenever). This will max out your computer, and provide a matched set.