I suppose the honest answer is I dont know what I want :-) This is my reasoning.
It is a notebook thingy (asus) a few years old, I only use on hols a couple of times a year. It currently has 1GB of RAM. Although not all the laptops fault some hotels the internet is sluggish. I normally take loads of pics transferred from my camera, check email,my ebay accounts and usually load a couple of spreadsheets I can work on while wife sunbathes or shops. I may go in to a few forums. I find that the at times loading images or working on spreadsheets a bit sluggish but not unusable. So I saw a 2GB RAM for £6 on ebay and decided it can do no harm putting more in, if anything it may improve performance. I have no idea on the technical side of this.