holy smokes - first of all, thanks for so many replies so fast. it sounds like converting an old mountain bike is a good cheap way to go. 3 questions on that -

1. do they hold up well under load? I plan to primarily use this as a lug-stuff-around bike
2. any particular models to look for (or ones I should avoid)? I know of the Specialized Stumpjumper (just missed one on CL!), any other ones that are especially suited to a touring conversion?
3. is geometry/riding position the only main difference b/w a 90's mtb and a touring rig?

ironwood - I meant mountain bike tires. 650B's seem much harder to find =\. do you have a link to the article in the touring sub-forum? I'd like to read up on that.