Last December I ordered a 1 GB memory chip for my laptop and it worked great until about a month ago when suddenly my computer would not boot up with it installed. Something had gone wrong. Faced with the possibility of having to buy another one, I emailed the folks at 4 All Memory and asked them if I could get a replacement. The coolest thing was that they replaced it for free (all I had to do was mail my old chip back).
So if you need to order memory for your computers I’d recommend 4 All Memory. They have a lifetime warranty and they apparently mean it. From their web site: Lifetime is defined as the lifetime of the product on the market. Outdated technology is not covered by lifetime warranty if the item is no longer available on the common market as a new product.