My 4-year-old grandson was kept home from school sick and stayed with Grandma and Grandpa yesterday. We hauled out the old 027 track and created a 19-foot irregularly shaped setup using 027, 034, 042, 054 and 072 curves. A cheap old Marx set came off the display shelf. A little cleaning of the track, and away it went, powered by a 30-watt transformer.
Of course, after a bit it was on to the Nintendo DS.