The Gallery2 Image Extractor Content Plugin lets you insert images from your Gallery2 albums into your content pages.  You may be familiar with the G2 Image Block module; this is similar, but provides a way to show the image block in your main content rather than in a module.

How it came about

Joomla has many strengths, but in my opinion also has two significant weaknesses.  The first is its lack of flexibility in role-based permissions management, specifically, the ability to assign users to arbitrary group.  The second, and most relevant here, is how difficult it is to cross-link to other content and images within the same site - something that Wiki does very well.

For cross-linking to other content, I recommend the Titlelink plugin, which lets you do things in a wiki-style way.

There are other modules for picking up Gallery content which are worth looking at.  My first choice would have been Gallery2 Image Chooser, which provides a thumbnail chooser in your HTML editor.  Unfortunately I couldn't get it to work for me, despite following the installation instructions to the letter and checking it twice.  My next choice would have been  Gallery2 Bridge Keyword Image, which allows you to pick an image from the gallery by specific keyword, keywords taken from the content, or (like the G2 Image Extractor) by specific image ID or random selection.  To provide the clever keyword functionality, the G2 Bridge Keyword Image needs to make its own connection to the database, which is where it fell over when I tried to install it; I got an error pointing to a missing table, so, I regret to say, I had to uninstall it and move on.

The G2 Image Extractor is really a subset of the  G2 Bridge Keyword Image plugin, but so much simpler and hence, I hope, more reliable for installation and use.

Download 

Gallery2 Image Extractor Content Plugin

Documentation 

Gallery2 Image Extractor Documentation