Check out some of the most geeky wedding rings in the market. Double helix eing, engagement rings and some more can be listed as some of the nerdy engagement rings in town. If your partner is geeky enough, such rings can be a perfect engagement ring.
Create your own dip dyed shoes. You don't have to particularly use yellow dip-dye. I've tried this myself, and I dip-dyed my shoes blue and green instead. It really works! Make sure you have white shoes only, or else it won't work.