OpenShot is one of the best non-linear video editors coming up for Linux. You can install development version of OpenShot by adding ppa:openshot.developers/ppa to Synaptic>Settings>Repositories>Other Software>Add. Then, it can simply be installed from Synaptic Package Manager.
Install OpenShot in Ubuntu 9.10 Karmic Koala and Ubuntu 10.04 Lucid Lynx
