Cheers for the comments guys. Zero nails the issue in that I need to export to see the image changes – non destructive image editing in Lightroom is very nice until you want to see the changes elsewhere. I'm going to go with exporting my fav's into iPhoto and live with the duplication. It's not like I take that many photo's anyway, or indeed have that many 'good' photo's. Just like everything quite clean and simple.