In reply to Gills:
> Does it not make sense to wear a harness even soloing? I realise it mostly wouldn't be put to much use other than carrying shoes, but if your to get cragfasted would it not make rescue easier?
That's correct, though I suspect most soloists don't set off on a route thinking they may become cragfast.
Another use of a harness can be to carry the guidebook (in pouch, clipped on) on a multipitch route. That said, a wee rucksack would also work for that.