Is there a way or an extension that allows the site administer to see all the items associated with each tag?

The tag page (v2.6.8) shows number of items associated to each tag, but a list of the specific items.

Hello Joe,

Unfortunately I do not know of such an extension.
I only use the frontend for such tasks.

Although I am sure you know this, in the upcoming v3 however you can sort items by tag in the backend.

PERFECT - Thanks Krikor, I have not installed K2v3 as of yet.

One more question - in K2v3 would I still need to use the hidden menu with an empty category trick for tags that are not associated to a menuID?
I would prefer not using domain.com/show/tag/tag-name and instead just domain.com/tag/tag-name

I am also open to .htaccess solution if that's an option to hide the /show/ from the URL.

I know Joseph question is not about this. Triyng to demo a cool Joomla theme and K2 to see if it worths switching fron Wordpress I currently use, to joomla, had a problem with K2.

Discovered that it wasn't from the plugin but my Joomla installation( Hostgator dumped softaculous and offer only their script installation software wich is a piece of crap) so, the problem is fixed but in the meantime, searching for a fix discovered the V3 beta release of K2 and it looks awesome. Any news about a final beta release or even better, the alpha one? :D

Good Day George...here's the official Twitter post from JoomlaWorks regarding the status of K2v3...
Invalid consumer key/secret in configuration

I just realized that I had the following main K2 parameter off which allows for tag sorting in the backend:
Allow item filtering by tag (in the backend)

screenshot:
snag.gy/30Nkc.jpg