I have read the "documentation" on www.joomlaworks.net/content/view/51/41/

I can't get flickr to work.

1. I got the api for drjillgoldman.com but I do not see if there is a place in joomla/k2 to paste in the key and/or secret.
2. I have admintools and my permission have been fixed.
3. The one issue could be that I am not using drjillgoldman.com during construction.

All I see on the frontend is:
{gallery}www.flickr.com/photos/82613988@N03/sets/72157630570761288/{/gallery}
on this page:
50.116.122.123/~drjill/index.php?option=com_k2&view=item&id=81:brandi&Itemid=282`

sigpro Version 2.5.3 
k2 2.5.7
j 2.5.6

Here is my contribution to the community....

My issue was that Flickr had restricted my account because I had "adult content".  As you can see in the Image Gallery they are just images of an Online Printing Company website.  www.modernmagic.com/web-design/isl-stellar-print-network.html

So if your flickr integration is not working you should check no your accounts restrictions.