Originally Posted by mmeiser

If you want to go nuts get a titanium Fargo and a second set of lighter/ more road specific wheels. I love riding my to Fargo with 38mm tires. Indeed the stock rims are fine, but you could go lighter. Next option is the vaya or colossal or any of the salsa road bikes.

As a class of bike I highly recommend cyclo cross bikes for ultralight touring. Far more versatile but just as close to fast and light as a road bike. I have a carbon fiber Cronus from Trek. Weighs in at 19lbs with 38mm tires and less then 30lbs fully loaded. I do ride it on local club rides with 23mm tires and its every bit as quick as a road bike. In the winter I'll even ride studded tires on it.

I use revelate designs bags which are available through most bike shops now and worth their weight in gold.

If you want value a good cross like the Surly Cross Check starts at about a grand.

Cross are a little shorter wheel base then touring, a little more aggressive geometry, lighter and much quicker to climb. All these are much more suitable qualities when you're carrying less then 20 lbs of gear.

That said the thing I love about my to Fargo is it is completely Jekyll and Hyde. When I put the handlebar up and my brooks on the thing rides like a horse. Bolt upright with a thudbuster seat post bouncing along. But I can and do throw some 38mm tires on it get into the drops and take it on 20+ mph rides. It hauls but and clubs much better then it should with its relaxed geometry. BTW, with STI shifters and some 2.2" tires it is a singletrack demon. It is perhaps the most versatile bike I own.

Will try to post some pics. They are on my flickr feed. Flickr.com/photos/mmeiser2

Oh yeah, almost forgot. Another class of bikes you should research are randoneering bikes. These are not made to race but they are often made of practical materials like steel, somewhere between cross bikes and traditional touring geometries for comfort and performance over ultra endurance distances. They are lighter then traditional tourers and made for carrying gear and can usually accommodate more practical tire sizes like 28-35mm as the cross and touring bikes do. Indeed one of the most interesting things about randonee bikes is that they have some interesting alternatives to bikepackjng frame bags. Specifically caradice seat bags and handlebar bags.