I still use xv daily. I paid the sharewire price back in the day (I think it was $25), and the license, if I recall correctly, was a photo of John with a thumbs-up. I've added a few patches here and there to deal with slightly more modern jpeg features and the like, and for the most part it handles everything I want to do, and the rest I do with imagemagick. For just looking at images I use xv all the time. Fast, and with some editing options as others have mentioned.