Originally posted by ib_inked
The best way to ground yourself when working on the internals of a pc is to touch the metal case inside first.
Yes that is correct, as long as the case is still connected to a ground source (three-prong wall plug). The metal case standing alone on a table is not a ground point. Touching the case while it is not grounded will only bring you and the computer to the same potential. That helps, but at some time, that potential energy on the PC will have to be discharged somewhere, and it may not be controlled.
And to avoid the problems with a wrist strap cord getting in the way, try it as an ankle strap. It will work as long as you got the metal part of the strap on your bare skin.