Wow, folks have some great ideas here.
We took some giant eucalyptus logs (10'x4') and made benches out of them. This was a lot of work with a chain saw, hand saws, hammer and wood chisel and sand paper but it was finally down. We took the leftover wood and chipped it down. They're pretty comfortable and pretty functional. I carved tables into the arm rests and everything. One of the smaller logs was made into a bird bath also. We stood it upright, carved a basin into it, sanded it down, used a non toxic water sealer and filled it with water.
From my days of working in the labs. I had about 500 cylinders, beakers and misc glassware that we have turned into shelving. We took a bunch of cylinders, filled them with colored or painted rocks. Others with water, gelatin and food coloring. They were all corked and then we took 2 boards, one for the top and one for the bottom. Each corner was reinforced with a 2x2 support beam. The back and the sides were lined with the cylinders which were glue at both the top and the bottom. When place against the light or near a window they look really cool.