Is there a way to use the normal of a face to model something else? I was wondering if there's a way to extract the normal of a specifici face to use it later in something else

In my case what i'm trying to do is a pipe that, in its start point, goes perpendicular to a specific face of my model. So it would be useful to use the normal of the model to start a spline.

heres a pic:


Thank you!
You can also select the face, then "view->align view to selected->front" (shift Numpad 1) and then change the 3d manipulator to "view" (instead of "global" or "local"). Then you can extrude a vertex along the normal by pressing "E YY" or "E XX" or use the manipulator to move along the aligned view axis.