I've seen a number of little boys (2/3 year old) around with some great toy trains. they have working wheels, realistic puffing noises etc. They are about 6 to 8 inches long and look like vintage American steam engines I would say, quite detailed and shiny.
I would really like to get one for DS2's birthday as he's been snatching them from any child we see but need to direct the GPs to where they can buy one.
Ring any bells?