Edit Links in Office 2010

The Edit Links is no longer in the menu/ribbon in Office 2010, you have to turn it on.

PowerPoint

In Options, create a new tab and new group.

From All Commands, add "Edit Links to Files"

When you insert a picture or movie, from Insert drop down, choose Link to File

you can then use the new button to edit the Links (Note: The Update checkboxes are always dimmed for some reason, you cannot choose between Automatic or Manual, which could be handy to insert live graphics from file system [even better, if you can get real time feed from web like the addon liveweb http://skp.mvps.org/liveweb.htm])

Word

Similarly, you can do it in Word, except there are three options in Insert - Insert, Link to File, Insert and Link. Also more option in Edit - Locked Update, Save picture in document. see http://www.labnol.org/software/insert-images-in-word-documents/8144/ for details