For under $600, the best bet is to convert an old steel frame mountainbike to a tourer-rigid fork, semi-slick tires, front and rear racks. This can be done fairly cheaply as I recently turned this-> http://www2.trekbikes.com/bikes/bike...d=1033000&f=23
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http://www.nashbar.com/profile_morei...ku=9756&brand=
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http://www.nashbar.com/profile_morei...u=14136&brand=
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http://www.nashbar.com/profile_morei...u=17041&brand=
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http://www.nashbar.com/profile_morei...ku=7723&brand=

= A tourer under $600 I am well pleased with.

Some stuff about the OCR3. Great entry level road bike, but not a touring bike by any stretch of the imagination. It only has eyelets for a rear rack, it has no clearance for anything fatter than 700c X 28 tires, (let alone fenders!) it has caliper brakes, (you'll want cantilever, V-, or matbe disc brakes for loaded touring.) If you really have your heart set on the OCR, and can deal with the shortcomings, get a BOB trailer-> http://www.bobtrailers.com/ but keep in mind, you'll be on skinny racing tires with no fenders, and any panniers you can hang from the rear rack will probably strike your heels due to the short chainstays.

Also, something that is like the OCR, well-priced, and wouldn't be bad for tours is the Giant FCR http://www.giant-bicycles.com/us/030....asp?range=254 It's got v-brakes, the price is low enough to maybe also afford a BOB trailer off E-bay, and it has good tire clearance. Good luck, I hope I helped more than confused you.