Narrow gage is perhaps the fastest growing facet of 7.5" gage live steam. Hopefully by the end of the year, I will have my first firing on the new 2.5" scale C-16 I'm building (sort of... I'm making it a 2-6-0 to make it more managable). Also, 3.75" scale models of 2' gage are becoming very popular since you ride IN not ON. Do a search for the Sandy Ridge and Clear Lake RR, a private 3.75" gage line in Michigan that will blow your mind. It rises 90' from one end to the other. Out in Oregon or Washington there is a new 2.5" scale K-36 that is unbelievable.
www.livesteaming.com has enough links to narrow gage live steam models to keep you twitching for quite some time.
--Denis Larrick