Is there a way (or rather, a specific function), that would let me use the mouse wheel in my program (And detect if it's been "scrolled")? I'm coding a scrollable list of elements, and it would be nice if I could scroll it using said wheel.

mouse_z is your friend.

Check out mouse_z, I believe that deals with the wheel. http://allegro.cc/manual/api/mouse-routines/

Edit: 2 seconds late!

There is a variable called mouse_z thats value changes when wheel is scrolled.

[edit]
Three minutes late because I thought there was some kind of longer explanation about it in manual but seems there isn't

Oh well, it would be much more readable if it would be called mouse_wheel, but I guess it'll have to do. One other thing, is there something like get_mouse_mickeys() which returns the wheel movement, or do I have to code it myself (I'm lazy, I know )?

Maybe something like this

void get_mouse_mickeys_ex(int *mickeyx, int *mickeyy, int *mickeyz)
{
  get_mouse_mickeys(mickeyx,mickeyy);
  static int mz = mouse_z;
  if(mouse_z != mz)
    *mickeyz = mouse_z - mz;
  else
    *mickeyz = 0;
  mz = mouse_z;
}

Havent tested it, probably not thinking straight either because I just woke up, use it at your own risk