I kind of wonder if anybody have thought of doing the larger and more open COD4 maps like say Crash or Broadcast. While Shipment may be alright (at least when playing COD4 itself), it might be far more interesting to see other maps convert over to Quake 3, even if they're both really different games.
A well-placed Rocket Jump might get you to the crates in just the right spot. But I'm not sure a CoD map fits well in Q3... EDIT: It seems the RL is missing, so disregard that. Edited 6.01 hours after the original posting.
"Tigs notes: A simple Plasma Jump from a barrel will get you onto the cargo containers in standard Q3A." And Grenade Jump from grass too... And simple jump from the wooden box leant to a wall.