Grabs image thumbnails from Flickr's API, then uses @heptal's most excellent "image" function to convert them into images in your terminal. If you want to search Flickr for multiple tags simply enclose them in quotes. ImageMagick and Python are required to use this.

console_screensaver.sh

#!/bin/bash
# Set a higher ulimit so we don't segfault
ulimit -s 32768

search_string=$1
search_string=${search_string// /%20}

# Courtesy of heptal's Console Colors
# https://gist.github.com/heptal/6052573
function image() {
convert "$1" -resize "$2" txt:-|sed -E 's/://;s/\( ? ?//;s/, ? ?/,/g;s/\)//;s/(\w,\w,\w),\w/\1/g;/mage/d'|awk '{print $1,$2}'|python -c "import sys;f=sys.stdin.read().split('\n');f=filter(None,f);print 'tput rev;'+''.join([''.join(map(str,('echo;' if x.split(' ')[0].split(',')[0] is '0' else '','tput setaf '+str(sum(p*q for p,q in zip([36,6,1],[int(min(int(c),254)/42.5) for c in x.split(' ')[1].split(',')]))+16)+';echo -n \"  \";'))) for x in f])+'echo;tput sgr0'"|bash
}

# Rotate through the current set of images, then try to grab some more!
while true; do
  for url in $(curl -s http://api.flickr.com/services/feeds/photos_public.gne?tags=$search_string | grep -o 'href="http://farm[^"]*"' |  sed 's/href="//' | sed 's/"//' | sed 's/b.jpg/t.jpg/'); do
    image $url 75
    sleep 30
    clear
  done
done