Astromech droids with piloting skills in the cockpit prevents travel aborting if the pilot boards an internally docked entity. (
Link)
Droids can be used in ground combat much like NPCs (
Link) and can also be disabled and captured. (
Link).
Medical droids can be used to assist in cybernetic operations. (
Link)
LIN droids are used to assist in mining. (
Link)
TT-8L Sentry droids report the movements of PCs, NPCs and droids through the room they are deployed in to their manager. (
Read the description)
I may have missed some.