Much has been made of a possible bird flu pandemic, and Twitter might just be the answer to predicting it, if a new Twitter mashup has its way. SickCity calls itself “realtime disease detection for your city,” and gathers statistics by looking for tweets that specify diseases or feeling ill.The site also notes that they will be adding Facebook soon, which would add a significant number of data points to their feed of “sickly” information. The site scans for the terms flu, food poisoning, headcolds, chicken pox