At Pennsic XXVI, some friends of ours had these great wooden chairs. We'd seen similar designs before, but the ones Chadd and Morgen had were really nice and comfortable. They made a set as a gift for another friend, and we measured his so I could build my own.
They're stained to match the boxes I built.
The photo above shows our chairs in front of our tent at Pennsic. The two brown chairs are ours, and the lighter colored chair at the right belongs to Sir Maugnus. The angle it's at shows the contruction better.
These chairs are commonly referred to at Pennsic as "Viking Chairs", but I'm told that they have absolutely nothing to do with Vikings.
I actually used "PolyShades" from Minwax, a mixture of stain and polyurethane.
For tools, I had them cut the lumber to length at the store, and used a circular saw at home for cutting the tongue. I should have used a drill and jig saw for cutting the slot, but I don't have a jig saw, so I had to use a coping saw and cut the slot by hand after drilling the starter holes. (My hand still hurts).
All in all, this project only took a few days, but I rushed it so we'd have them in time for Pennsic.