My own metro

It started its life as a standard high speed Lego set, one engine with 2 cars. It's now a metro/subway set, raised to the second floor level above ground (so that HO could pass under it), featuring one cab car and 3 cars following, all of which bend in two places, for maximum flexibility. I've been able to run this train at max speed around the layout without derailing or tipping. You try that with a standard Lego set at full throttle. The secret is flexibility and low height - it's as tall as a standard HO locomotive. Thus it has the same engineering formula as a Formula I racing car - low height and ground clearence for maximum ground contact.

To see the train in action, please view these two video clips. I apologize for the low quality, but what do you expect from a entry level 2003 digital camera?
http://media.putfile.com/L33
http://media.putfile.com/L34