ScottishHills.com – An amazing resource covering all Munros, Corbetts, Grahams and now marching its way through the Marilyns

Walkhighlands – loads of detailed walking routes.

The Mountains of Scotland – Marilyns, HuMPs, Donalds, Tops – a great hill locator.

mwis – my weather bible

Geocaching.com – A great resourse for finding local info and walking routes you might not have known about.