Any one know if it's possible to simply swap the two front seats round, could I just unbolt each one and swap.....my drivers side is more worn and the passenger in nearly new condition?

Not really as the seat side airbags would both face each other towards the centre of car rather than the doors!
You would also have to swap all the runners/subframe over as the seat belt pre-tensioner is bolted to the seat frame but the seat back release levers will end up on the wrong side of seats for rear passenger entry........can't remember exactly but the release cables and levers may also not match up on the other side runners, etc.

Any one know if it's possible to simply swap the two front seats round, could I just unbolt each one and swap.....my drivers side is more worn and the passenger in nearly new condition?

I wish this was possible, my drivers side is very worn at the door side and make me lean more to the right as theres no support. Found a pair of almost new leather seats on ebay at £75 so may possibly go for those.

It may be possible to swap just the seat upholstery covers over? the bit you sit on, not the backrest, (they are handed due to the airbag etc), by taking them off and changing them over? You can do this on some cars where the bases are not handed.

There are a couple of links to stripping and rebuilding Mini seats here:
Seat Problems & Solutions - Forums (http://forum.minicooper.org/showthread.php?t=12641)