[Ladada2001] sent along a project link for building a VGA extension cable using CAT5. This particular project was for a projector with BNC connectors. This has been a particularly popular (and easy) topic in the past. We’ve seen an example from ElephantStaircase. The 5-in-1 cable featured in Make also had provisions for VGA. If you build one of these cables you should be able to get decent performance at 50 feet.