It's not quite a startup, is it, but it's cute anyway: Tumbltape. Why open an account at a site like Muxtape that's going to get shut down for exceeding their bandwidth costs or getting in trouble with the RIAA or having even the vaguest association with trouble-prone entrepreneur Jakob Lodwick? Tumbltape makes a playlist from the songs you've already uploaded to your Tumblr blog. The site was made by Adam Gotterer and John Zanussi (in the hoodie, left), both of Connected Ventures — Lodwick's former stomping ground. Those MP3s aren't going to play themselves, so get to it. (Photo via The Daily Zanoose, a Tumblr devoted to photos of nothing but John Zanussi)