Megabus is a new budget double decker bus service operating between Edinburgh, Glasgow, Dundee, Perth, Aberdeen and Inverness. Tickets from as little as £1.
The Scottish Citylink coach network operates the main routes between Inverness and other towns/cities in Scotland (e.g. Fort Augustus, Fort William, Oban, Skye, Ullapool, Wick, Aberdeen, Perth, Edinburgh, Glasgow, etc.). Visit their web site for timetables. You may be able to benefit from the Explorer Pass which offers for unlimited travel between certain dates. Discount tickets (Smart Cards) are available for travellers over 50 and for students aged 16-25.
Rapsons: Running local services on Skye and throughout the Highlands of Scotland.
National Express: Running express coach services for the whole of the UK.