oh yah, whats the distance/anglething do, never seen it before
and are there more of them?
All system expressions can be found by double clicking the system object in the object panel in the parameters dialog - or look up 'System Expressions' on the Wiki.
If you have two points - (x1, y1) and (x2, y2), distance(x1, y1, x2, y2) gives the distance between the two points, and angle(x1, y1, x2, y2) gives the angle between them.
I'll come back to this when I have an internet connection installed in my house!