This is one of the most original methods to increase website traffic I have seen.
Every time you get paper money in your hands, write or stamp your domain name on it somewhere. Every person who comes in possession of that dollar will see your domain name. Ever hear of Where’s George? Their website is showing a Google PageRank of 6/10 right now, and TONS of people have heard of it.
This is probably illegal so don’t do it too much.