Partial Selection

[Fonte Boa]

I bring in a cube, select a face, extrude the face a little, hit D to repeat the action, now what I want to do is to increase the size of the face bigger than the cube (sort of a scale command) but I just want the face only to extrude outwards.
is this possible ?

Instead of Face|Extrude, explore the two following commands, by which you are able to extrude and scale simultaneously using a single command (ever keeps an eye at info line to know how to proceed):

(a) Face|Inset
(b) Face|Sweep (more powerful yet, since it allows you to rotate the face that are being extruded).