More Delete and Copy Tricks To Add
brnxblze, here is another delete trick for deleting multiple objects at the same time that are not attached to each other.
Place your cursor at a point just above and to the left, or right, of a group of unattached objects that you want to delete. Press and hold down the "X" and draw a select box around all of the objects. This will select every object that is fully encompassed within the box. Now press "Triangle" and all the objects will be deleted. You can also press L3 to copy all of the objects, rather than delete them.
Notes: This technique works best with Grid On. And start the draw by holding "X" and moving the cursor straight down before moving the cursor to the left or right. This prevents the select box from shifting to the right or left when the view begins to Pan.
Rick