CO did have a type of personal television IFE system on some aircraft that, as pointed out, provided gate information, video games, and other information, but I recall the system being installed in the CO
733s....I did not think that the 757 fleet had that type of system as they were delivered much later on. As pointed out above, the entertainment system was developed and marketed by a company that later went broke and out of business and no maintenance or spare parts were available, thus, the system was removed. I think that America West had a similiar system for the same supplier on some of its 737s, which is also now being removed as aircraft are refurbished....its now just extra weight.
also equipped some of its 733s with video monitors for movie presentations, back then, as the 733s did some longer-haul routes such as EWR
(now 737NG territory), many of those aircraft now fly CLE
-Florida routes and the system is sometimes used for Continental Vision inflight entertainment.