Some great info here but I just wanted to throw in that you can get a pretty cheap scanner from kaiser baas BUT the scan quality isn't that great. They're pretty cheap on ebay and really fun and great if you want to quickly go through old family negatives and take a trip down memory lane BUT not so great for digitising any 35mm pics that you want to post to flickr or edit greatly etc. before resizing they're less than 500KB.
here's an example of one scanned by this scanner kaiserbaas.com/converters-category/photo-and-negative-scanner -