miauu's Unhide by Select
This script allows you to unhide hidden objects by selecting them via mouse click or via Select From Scene dialog(H hotkey).
How to use it:
1) run the script - all visible objects will disappear. In the viewport you will see all hidden objects. If the script is assigned as a toolbar button it will stay pressed.
2) select the objects which you want to unhide.
3) run the script again - in the viewport you will see your original visible objects + the objects you have selected.