They're the hoses that connect to the vents on the top ends of the dash, the solid plastic ones that fire the air at the side windows. Shouldn't be a problem to reconnect if they were taken down from the vent end but if they've been removed from the heater box end I could see the drivers side one being a bugger to get back on.
Naa, shouldn't be, if they've come off from the vent end then they slide fit on just above the plastic pipes that feed the front facing vents. If it's from the heater box end you may have to take the instruments out to get to the drivers side one, the passenger side you can get to easily enough, might have to drop the glove box down and/or the fuse box to get it there though.
I would point you in the direction of Vagcat to get some idea of what it is you're looking for but it doesn't appear to be working for me at the mo ... ?