Adding/aligning to normal(s)?

Hey,
Does anyone know of a way to add and/or align stuff to a surface’s normal(s)? Would be very helpful.

Thanks.

well a normal is always orthogonal to a surface , so all you really need to do is add 90 degrees to that surfaces rotation and apply it to the surface your trying to align.

Yes, I could do that, but I’m afraid it won’t work as intented in this part of the mesh I’m working on (that’s the first thing I always do at similar situations).

There’s a similar question here:
http://blenderartists.org/forum/showthread.php?t=85864