I've been busy researching book promotion on the internet. I have come across many wonderful suggestions, such as wearing a business card as a name tag in order to start a conversation and book giveaways on your website and other websites (with permission with sites owners, of course).
There have been many unusual promotions that I have uncovered. There is a young woman in NYC who hired several actors to read her humor novel across the city. They were to laugh out loud and create interest in the book. It worked well for her and sold several hundred copies. I have read that other authors found this unethical. I think that if I works and it doesn't hurt or degrade anyone, then do it. Another author created a cereal to promote his book.
I purchased car magnets from Vistaprint (they do a pretty good job, but I'll leave them for another time) and drive around with them, whether it be to the store, work, or the NYS Thruway.
I have had large postcards made up and attach a sample chapter to the back. Invariably, people pick them up and take them away with them. Whether they are effective or not is hard to determine, but it gets the word out. For my Miss Mary Pennynickle books (Miss Mary Pennynickle's Tales of Torment for Toddlers and Miss Mary Pennynickle's Fairytales of Foreboding) I have had friends leave small postcards behind at bars and clubs.
Well, off to the internet for more ideas.