This one of the google widgets to display flikr from user chalkhillian, change every 60 seconds, display 4-up in a block on geeklog. Paste the full script into a block and voila. Any of the 1500+ widgets install quite easily as scripts in blocks (if they fit) - I also use a google community calendar widget at
hereText Formatted Code
<script src="http://gmodules.com/ig/ifr?url=http://chinsonyeh.googlepages.com/flickr_google_desktop.xml&up_username=chalkhillian&up_count=4&up_display=random&up_tags=&up_interval=60&synd=open&w=100&h=350&title=Flickr+Photos&border=%23ffffff%7C0px%2C1px+solid+%2399BB66%7C0px%2C2px+solid+%23AACC66%7C0px%2C2px+solid+%23BBDD66&output=js"> </script>