I didn't knew it would look that big! Compared with the largest of the moon's craters the ISS seems to show more-or-less the same angular diameter, which is quite encouraging, because I really want (or should) aim my ORION-SKYQUEST Dobsonian XT-8 reflector telescope at the ISS! I just need an open space to follow it (the ISS) from somewhere above the western horizon while it is ascending all the way toward the zenithal region, and gradually descending toward the opposite (eastern) part of the horizon.
I was once an airplane spotter, and back then it was piece-of-cake to observe an airplane through my humble 5 cm VIKING refractor telescope (those were exciting days!). Perhaps I'm about to become an ISS spotter? Who knows...
Danny