I have a fuji S100FS and i have found that the RAW function gives me the best quality photos but, when i upload them to my PC i can not open or edit them.
All RAW files need processing with conversion software to a standrad format like JPG. The S100fs is supplied with FinePix Studio (on a CD) which will do the converision (although slowly and with a poor user interface). You can also use any recent (newer than the S100fs) Adobe program like Lightroom, Photoshop or Photshop Elements. I'm sure many other RAW-converision packages/Image editors also support S100fs, but I don't know which. Supported cameras are usually listed on their web pages though.