<p>Just wanted to say that, thanks to this thread, I was able to plan out how my wife and I would carry our kit to Iceland. We've each got Lowepro AW-type cases and have simply bought a bunch of carabiners with which to secure them in front of us to the shoulder straps of our packs. A little experimentation suggests that two clips on one shoulder strap and one on the other should strap gives you a good balance of security (3 clips in all) and quick-ish entry/exit (you can remove the pack by only unclipping one carabiner).<br>
Will send a photo after the Laugavegurinn. :-)</p>