Look to the United Kingdom for expertise in quality steel frames that range from ordinary credit card touring right through to the tough type of expedition bike that you think you want. Thorn comes highly recommended, particularly the 26"-wheeled Expedition model.
As to the "you think you want", I have just ticked over 33,000km on a 2001 Fuji Touring, and the frame has served me well. It has 700C tyres, and can take at least 32mm tyres. Its duty has included Australia and Europe (North America awaits). I am more a sealed road rider these days, but with TT2000-32 tyres it can handle gravel roads quite well. Other options are available in North America. A recent thread on the iBOB board listed quite a few bikes suitable for touring purposes.
Incidentally, there is a lot of debate about aluminium versus steel. I am a steel person. My main concern is the rear derailleur hanger and the inability to adequately repair an alloy one over a steel one. I've bent mine once, and had no qualms about gently bending it back into shape. I wouldn't have done so with an aluminium one.
Last edited by Rowan; 03-05-05 at 08:33 PM.