Customize each post so each post shows different photos

I have a personal travel journal website. I have it working so each of the posts has different photos in the sidebar (pulled from flickr).
http://bexesler.com/trippin/

The only way I could figure out to get this working for now was to create a different sidebar file (each one contains code for different photos) for each one and create a custom field on each posts, that tells it to use a certain sidebar file.

Is there a way I can set this up to make it a lot easier to create each post, not having to create new sidebar files each time?? I dont know php….was thinking maybe something along lines of tagging photos and putting that tag in custom field so it pulls those photos. or a set name…??