Runners from more than 100 countries participated in the Bank of America Chicago Marathon on Oct. 11. Many of those people and their supporters turned to social media to post photos and express their emotions ahead of and during the event. The above mosaic shows social posts from people along the race course, overlaid on a photo from the race. Were you there tweeting? Use the 'Find Yourself' tool to find your post or click on the faces to see posts by others.