DIY natural swimming pool - the video provided in the link is pretty cool. I've had dreams of these things, and now that I've seen an actual video I'm a bit kreeped out because I don't like swimming in dark water, but the pool itself is pretty awesome
Use Old Crates and Drawers as shadow boxes. I love this. Went through my Dads barn and found some old crates and boxes that my Grandfather made to store nuts, bolts, screws, etc. I have them hanging on my wall now.