Many uses :)
Using as a mark for many objects (origin), or as a special mark on an object who is not a "snaping point"
For many Alignements
For constructions helpers lines untill Michael will find some "layer" for keep the help lines :)
because now helpers lign disapear when you draw an other object :D
Or for tricky thing like when you have little object and big object and want make some special zoom or hide something...
just put single point on left and right of these objects :)
...and surely you will find by yourself some useful use of it :)