Ignore cache for specific block

Hello everyone
I would like to ignore the cache for a specific part of my page. In my case, there is a random image gallery that is not so random any more since it is only updated if the page is updated too. As the images come from other pages, always saving the homepage (where the images are displayed) is not that practical.

Can I ignore that part of the page?
Thanks.

You could pull in your images with Ajax.