Update, over a year later! There
are proper maps (Ordnance Survey Explorer sheets 362, 363 and 364 show most of the Way and are at 1:25,000) and we are about to publish a proper
guidebook. Even better, the Cowal Way has now been extended to 57 miles (92 km) and it links up the Kintyre Way with the West Highland Way.
I walked it in February 09, and it's a great combination of sea lochs, rugged scenery, forest and moorland and accessible wildlife. It's more strenuous than you'd expect from the overall distances, with some challenging terrain in places, but well worth doing.