Here are a few Disney World Train decorations from last year:
One of the Walt Disney World Rail Road engines parked in front of the station that was decorated for Christmas:
The train under the large tree when you walk into the Magic Kingdom: (The engine says Lilly Belle and the caboose is lettered for Carolwood Pacific)
A Christmas train running on the G Gauge layout at the Germany pavilion at Epcot:
The train layout they assemble in the Lobby of the Yacht Club resort:
I'll try to come up with an O Gauge pic or 2 tomorrow.
-Dave