Ideas for a bottle cap mosaic?

I am planning on making a bottle cap mosaic and have about 2000 bottle caps of various brands of beer. (No I did not drink them all myself.) My hubby and I have been brainstorming for about 3 months and then it dawned on me that I could ask on here for outside ideas. I have not decided if it will be a hanging mosaic or a table top or something. Grout is not out of the question. No idea is too dumb. Thanks in advance for your suggestions!!