rootsh is installable through Hildon Application Manager. You will need it in any circumstance where you need root access to your device.

rootsh will ask for a sudo password, though, so on top of rootsh you can either install sudser, to be found here
http://maemo.org/packages/view/sudser/

Or you can manually edit the sudo requirements in
/etc/sudoers.d/01sudo and add sudo as a passwordless command.