Frustrated by a lack of access to your thoughts and feelings about world events and sandwiches circa 2008? Twitter's working on a way to let users export and download old tweets into a file, according to CEO Dick Costolo. As far a service for search all users, the exec doesn't see such a solution coming any time soon, telling reporters, "It's a different way of architecting search, going through all tweets of all time. You can't just put three engineers on it."Filed under: