Previously we told you about TweetForATrack a site that will allow you to trade a download for a tweet to spread the word about your music across the Interweb. One of the cool features we discovered once we got to using it was that it also collects the email addresses of everyone who gets this download. It will let you export everyone who enters their email address into a .csv file which you can use to build up your mailing list. This kills two birds with one stone and helps to build your fan list and a lasting relationship with people who have your music. Too cool!