How far away can one send a servo skull?

I was thinking of giving mine Shadowing (+20) skill and using it to follow people. Or just flying it over the ridge to see what the foes are doing without exposing me to enemy fire/prying eyes. Or leaving it under a seat to listen in on conversations while I leave the building and do other stuff.

Is there anythign in the rules about such things?

Well it has stats and, given proper control via some sort of link up with the controller (a hand held device or implant) I don't see how it would be difficult too figure out. Just use it's stats as normal and figure out with your GM a reasonable distance it can traverse while still maintaining control or how well it can follow orders when outside that direct control range.

Book of Judgement limits servo-skulls and the like to an operational area of about 50m of the user, although it should be noted that these are Arbites-pattern and used exclusively in combat zones. An order like "Remain out of sight in this area for six hours, recording everything that you hear" should only be a +10 Tech-Use Test, while ordering the same servo-skull to follow a specific target, only activating its recorder if the target mentions a particular code-word or meets someone else, should pile on the penalties a bit more.

Virtually unlmited range, but limited control-range.

Tech-Use to give it orders when moving outside of control range.

That sounds reasonable.

My void-mistress has a servo skull, named I1 fitted with a multikey and trained in security. They can sneak around together and the little guy can open locks and stuff for her.

Security sounds cool.

I think I might do that myself, though, and use Noviate Robertus ("Bob") for scouting/eavesdropping.

Although it was suggested giving him Carouse skill!