Repeating an operation (similar to screw) In 3DSmax (I forget the name but I'd know it if you saw it) you can define a (simple - as in TRS only) procedure that will be repeated n times. Like screw.

Suppose I wanted to extrude and slightly scale down, extrude and slightly scale down, rather than doing it 15 times say, I could just use this?

How can I do something similar?

(If the scalar is &lt; 1 then it will form a curve shape)

Actually it'd make more sense just to attach a cone. So this question is two fold, how may I glue faces from a different shape together, and is there a more general version of screw? (In 3dsMax is was a dialog with a table full of input boxes)
You can always resort to F3 to view the history and repeat extrude region and move alternating with resize. it will always extrude the same distance and resize the same percentage relative to the size of the face that's been extruded. 

F3 > extrude region and move, F3 > resize and repeat.