Themes: where can I put a link to an affiliate script?

Which template are you using? What level do you want this link to show on, i.e., collection, album, or full picture?

It doesn't appear that you are including any descriptions with the images, so that's a good place to add this in the template.

Open picture.php in your theme and locate the following code (you may or may not have removed the plogger function to display the description already):

print '<p id="description">' . plogger_get_picture_description() . '</p>';
To display your link under every image, change it to read:

print '<p id="description">'<a title="search for this poster on ebay" href="link to your script here">search for this poster on ebay</a>'</p>';

Try the following and let me know if it works for you:
print '<p id="description"><a href="http://www.freefilmposters.com/go.php?'.plogger_get_picture_caption().'">Buy '.plogger_get_picture_caption().' posters on eBay</a>';
I changed the variable $picture_name to the actual Plogger function for displaying the image caption.

edit: sidtheduck fixed single quote and double quote issues.

I just did an update to the VERSION: 1.0-RC1-Rev601 and I need this to be done again from scratch! Should I change the same code in the picture.php of my theme? Sorry if this is a silly question but the code looks slightly different and I just want to be on the safe side.... I am using the Classic theme Version 1.2....
also how do I remove the View Image Details and the date??
many thanx in advance!

strange but I still see both date & image details... here is what is left in the code for your to check...

<?php plogger_get_header(); ?>

<div id="inner-wrapper">

<div id="big-picture-container">
<?php if (plogger_has_pictures()) : while(plogger_has_pictures()) : plogger_load_picture(); // Equivalent to the WordPress loop
// Find thumbnail width/height
$thumb_info = plogger_get_thumbnail_info();
$thumb_width = $thumb_info['width']; // The width of the image. It is integer data type.
$thumb_height = $thumb_info['height']; // The height of the image. It is an integer data type.
?>
<table id="caption-date-table">
<tr>
<td><h2 id="picture-caption"><?php echo plogger_get_picture_caption(); ?></h2></td>

</tr>
</table><!-- /caption-date-table -->

<table id="prev-next-table">
<tr>
<td id="prev-link-container"><?php echo plogger_get_prev_picture_link(); ?></td>
<td id="next-link-container"><?php echo plogger_get_next_picture_link(); ?></td>
</tr>
</table><!-- /prev-next-table -->

<div id="picture-holder">
<a accesskey="v" href="<?php echo plogger_get_source_picture_url(); ?>"><img class="photos-large" src="<?php echo plogger_get_picture_thumb(THUMB_LARGE); ?>" width="<?php echo $thumb_width; ?>" height="<?php echo $thumb_height; ?>" title="<?php echo plogger_get_picture_caption('clean'); ?>" alt="<?php echo plogger_get_picture_caption('clean'); ?>" /></a>
<p id="description"><?php echo plogger_get_picture_description(); ?></p>

</div><!-- /picture-holder -->

</div><!-- /big-picture-container -->

<?php echo plogger_display_comments(); ?>
<?php endwhile; ?>
<?php else : ?>
<div id="no-pictures-msg">
<h2><?php echo plog_tr('Not Found') ?></h2>
<p><?php echo plog_tr('Sorry, but the image that you requested does not exist.') ?></p>
</div><!-- /no-pictures-msg -->
<?php endif; ?>
</div><!-- /inner-wrapper -->

<?php plogger_get_footer(); ?>

Do you want the caption displayed? If so, which side (left or right)? Let me know and I'll get the picture.php code worked up for you.

yes please I want the caption displayed on the left

If you have copied and renamed your theme folder, make sure to go the Themes page in the admin section and select the modified theme as the one you want displayed. If you still have it set to Classic (default) then that could explain why you aren't seeing the changes.

Elias: To change the name of your custom theme, open meta.php in your custom theme's folder, and make the following changes to the code at the bottom (lines 14-19):
$theme_name = 'Free Film Posters';
$version = '1.0';
$author = 'Elias';
$url = 'http://www.freefilmposters.com/';
$description = 'This is the custom Plogger theme for Free Film Posters. It is a modified version of the Classic (default) Plogger theme.';
$license = 'GNU General Public License (GPL)';
That will show your custom theme with the name you have given it, rather than having two Classic themes.

Glad that it's all gotten sorted out for you. :)