I'd like to schedule a big load of tweets so that they go one after the other at regular intervals (say, about 2 hours). I've seen some sites (like twuffer.com) that allow you to schedule tweets, but it must be done one by one. This is not feasible for my project, I need something more "batch-like".
Ideally what I'm searching for is a site where I can upload (say) a google docs or excel spreadsheet with the texts and desired post dates of all the tweets.
Do you know if anything like that exists?