Bumblebee 3.2.1 Released With Ubuntu 13.04 Fixes, New Options

Bumblebee 3.2 has been released a few days ago but there was an issue and it didn't work on a lot of setups o version 3.2.1 has been released to fix this. The new version also fixes the Primus backend for Ubuntu 13.04 and adds some new options.
Bumblebee is an unofficial tool that brings Nvidia Optimus GPU switching to Linux. It's useful to increase battery life by only switching the dedicated GPU (Nvidia) on when needed. Nvidia has added initial Optimus support in their latest 319.12 beta drivers, but it doesn't have GPU switching yet.