I finally got round to it, and created the brochure addon. Unfortunately it's just a plain html brochure, but maybe some day someone can use this to turn it into pdf.

Below is the included readme file for instructions:

The brochure addon allows you to select several fields from your database to show on a seperate page without your website layout around it. This can be useful for a wall paper or just a regular brochure for visitors to print out. It's a bit more advanced than the regular printer friendly option, since this just prints your listing view without any additional information or a nice layout.

The addon comes with a template and a css and language file that you can alter as you wish. 

The following tags can be used:

{addon_brochure_loadjs} - This tag loads the javascript needed for the popup window. The tag must be used in conjunction with {addon_brochure_url}
{addon_brochure_url} - This is the only tag not used inside the template. Use this tag for generating the url to open the brochure window. Use it only on a page where listingID is defined and in conjunction with {addon_brochure_loadjs}.
{addon_brochure_display_topleft} - same as {top_left}
{addon_brochure_display_topright} - same as {top_right}
{addon_brochure_display_center} - same as {center}
{addon_brochure_display_feature1} - same as {feature1}
{addon_brochure_display_feature2} - same as {feature2}
{addon_brochure_display_bottomleft} - same as {bottom_left}
{addon_brochure_display_bottomright} - same as {bottom_right}
{addon_brochure_display_image} - displays the first image in rank for a certain listing
{addon_brochure_price} - displays the price of the listing (properly formatted)
{addon_brochure_close} - display a url with link text to close the window
{addon_brochure_print} - displays a url with link image and text to print the window
{site_title} - same as {site_title}
{addon_brochure_css} - displays a link that includes the addons css file (put in header of template)
{template_url} - displays the templates url
{load_js} - same as {load_js}
{license_tag} - same as {license_tag}

Installation:

1. Unzip all files to addons directory (make sure the file addon.inc.php is in the directory addons/brochure/)

2. Start your admin panel. This will install the addon and the database table properly

3. Go to the edit brochure page and select the fields that you want to show on the brochure.

4. Add the tag {addon_brochure_url} somewhere in your listingview page and that's all.

I would really like to get some comments on this addon. I am not a very good programmer and am still trying to get the hang of it all. So any improvements or suggestions are very welcome!

[B]Release note v1.0.1[/B]
bug fixes
- The brochure crashed the site when a page without listing ID defined was loaded. I forgot to check whether listingID was set.
- added a tag {addon_brochure_loadjs}. I forgot that I used a javascript for the popupwindow that I had included in my listingview template file. This tag loads that javascript.
- changed installation function, so that the new version nr is put into the database