Anyone know where I can get 9volt (runs on electricity rather than batteries)? I would like to get the kids a set for Christmas. Thanks!

We always have good luck on Bricklinks.com. You can find everything lego there. Good Luck.;)

lego.com has some 9v trains on their site (the holiday and the hobby train)

9v are not made anymore, and the R/C line is about to be cancelled in favor of something along the lines of bluetooth. Its going to come out in 2009, so I'm holding out till then for the kids. thats all I know of it but you can read all the buzz at lugnet.com under trains.