I'd like to be able to place points on a plot using `Graphics[{Point[{a,b}],....}]` but have the plot symbol be an unfilled circle. I've looked around but can't find any way of doing this. Is there one? Thanks.

After reading the first response, perhaps I should add a bit more. I'd like to be able to do the following:

```
p1 = Plot[x^2,{x,-3,3}]
p2 = Graphics[Style[Point[{0,0}],PointSize[Large]]
Show[p1,p2]

```

but with an unfilled circle instead of a dot.

The solution proposed in the first answer falls short in two ways: first, the unfilled circle does not properly hide graphics elements underneath it; second, the circle will appear as an ellipse, not a circle, in the (likely) event that the underlying graphic does not have aspect ratio 1.

The application here is for plotting piecewise discontinuous functions and showing clearly which endpoint at a jump discontinuity holds the value at the point.