[dba-VB] VS2005: Create a rectangle in a PictureBox

Hi all

I have a form with a PictureBox, and I can load a picture from a file into this.

Now I wish to mark (select) a rectangle somewhere inside the picture - you know: mouse-down to mark upper-left corner, draw mouse to lower-right corner, release mouse button - and save the picture with the created rectangle overlayed.
Any suggestions on how to achieve this?

/gustav