memory question

I can't speak with a great deal of expertise on RAM, but I'd go for the cheaper option if they'll both work. Something I should note: You actually don't /need/ to increase you memory to install Linux. I've got Debian Linux running on a 400 Mhz laptop with 128 MB of RAM (using the Fluxbox windows manager.) Ubuntu 8.10 is supposed to run on a 64MB machine, although they recommend 384 MB of ram and a 1.2 GHz processor if you want 3D desktop effects. https://help.ubuntu.com/community/Installation/SystemRequirements. They also have Xubuntu which has a more lightweight desktop environment than regular Ubuntu, and would run fine on a 256 MB machine: http://www.xubuntu.org/get. If you are planning to play some powerful 3D games or watch DVDs, the (probably more important) question is: how powerful is your graphics card? You graphics card is what provides the 3D acceleration that speeds your games and videos up.

PerlCoder (http://indicium.us)

From what i know of RAM . If you all ready have 800 mhz ram and if you install 1066 hz it will just run at 800hz any ways because it will default to the lower speed stick. So if you install the 800 hz sticks your 1066 hz will run at 800 hz. It won't make a heck of a lot of difference, if the 800 hz will work with your gear. You won't notice a big speed difference unless you are a gamer. You should be fine with perlcoders suggestion if the ram is compatible with what you already have.