I am currently doing a woodworking hobby course at Belfast Metropolitan College.  My first project was an Adirondack Chair for my garden.  The chair is made out of cheep gravel boards from B&Q with the arms made from a decking joist.  Total cost was about £40 for all materials.  I will upload the Google Sketchup plans soon.  In the meantime here is a picture:

Adirondack Chair