We have several such floor outlets in some older areas at work. These have been retrofitted with RJ-45 jacks. The little oval "outlet-shaped" doors have sharp edges that flush fit into the flared recess. While they look cool and "antiquey" if they are placed right under a desk the occupant seems to use them as a "gas pedal" to make the computer go faster. What I mean is that with just the weight of a misplaced foot they end up severing (breaking ?) one or two wires inside the Cat5 jacketing after a while.
I haven't used one but this retro-modern model from Carlon has a large single door for plugging in jacks and a little cable door to route and (hopefully) take the strain off the cables. Maybe it will fit in well with your installation ?
[Link: carlon.com]