There are at least two more science film projects online, alongside SciCast; the Wired/PBS broadcast mashup Wired Science are soon to launch a competition for high-school students (scroll down), and New Scientist are running their own equivalent via YouTube.
I’m assuming the former is only open to US participants, but if you’re in the UK and enter the New Scientist competition, feel free to send your film to SciCast too — we’ll make sure it’s archived so schools can use it (YouTube is usually blocked by local authority firewalls).