Idea [#1] - Mobile Ad Campaign
I was thinking about a campaign that would use posters with unique codes printed on them and a persons cellphone. Ideally the codes would be 2d barcodes like QRCodes but that might not work in the US but maybe Japan. Otherwise you would need to use unique alphanumeric codes or unique keywords. You could then place them around a city or event.
When someone finds the poster they would take a picture of the 2d code or enter the code string into a url shown on the poster. If your the first person to enter the code then you could win a prize and all subsequent code submittions would receive a coupon.
From the marketing perspective it keeps your brand at the front of a persons mind as they hunt for your poster.
Another spin on this could done at events, expos... Have a group of people with codes on their shirts walk around, each different like a poster. The winners need to goto the companies both to redeem their prize. Last spin would really only work for 2d barcodes. Have a group of people with all the same code on their shirt and then one person with the winning code. Hold that person back for a bit of time and then have them wear a jacket to the middle of the expo and then reveal their shirt with the code.