Create free online music clips for use as ring tones, in podcasts, or other media projects. Arrange loops, record your voice, or upload your own mp3's to create your music. This could be a useful tool for creating music on a PC without Garageband.
Twitter has new photo filters powered by Aviary (an incredible tool that you can add for free, the last time I checked, to your school's Google apps for education account) it is easy to use. This article from mashable covers the changes but wonders if it is enough to pull people away from Instagram, who pulled the "twitter cards' feature earlier this week as more social media organizations try to claim "mine mine" over their users and don't want to share. Meanwhile, those who benefit, tend to be those who share the most.