For the slot car/train layout idea, if one has the space (not to mention the $$$), a 1 gauge layout in 1/32 scale would go very nicely with Fly branded slot cars (Fly are the most detailed. Carerra, Scalextrix, Monogram, and Ninco also make nice 1/32 scale slot cars).
Just to give you an idea of the scale accuracy and level of detail you can get with them (some come from the factory with working lights, but are not overly difficult to install in one that doesn't), below is a link to a C5 Corvette Convertible done by Fly.
http://www.flymodelcars.com/shop/e561-96017.html
Sorry about bringing back the slot car subject, but this is something I had thought about doing before I ever got back into trains.
An idea to do for the kids:
Though some small layouts have been done for this, how about an Island of Sodor empire. Done with Henry's Tunnel, Gordon's Hill, Tidmouth Sheds, the shipyard (for Old Salty and a working Cranky), the Quarry, Thomas's Branchline, the Scottish Castle, the narrow gauge railway, Harold's Airfield, the Smelter's Yard, the Scrapyard, and other spots seen in the Thomas the Tank Engine episodes (don't forget Sir Toppam Hatt, AKA the Fat Controller). Not just a few of the most used spots as is done on most Island of Sodor based small layouts, but a representation of the entire Island of Sodor (though there was no full layout ever built for the TV show). Even better, make it in 1/32 scale 1 Gauge, as the original Thomas engines were done.
Come to think about it, I may do an HO or OO Island of Sodor layout once I can get the space for an empire.
Regards,
Shannon