Help writing a cron job to get Flickr photos

You need to do two things which are separate cycles. The first is to write a script (in ruby or any language) to grab the flickr data. Once this script works from the command line you can instruct cron to execute the script at certain intervals.

To learn about cron, use google or man cron or man crontab.

Hope this helps.

You add a line to a special file called crontab. This line specifies how often a job should be run. Run a man crontab to check out the format or use google.