Stefi

It’s a tiny bit more flexible than wp native gallery. It finally allows non-linked images and images linking to external URLs. It also allows linked images/pages opening in a new page.
<h3>Usage</h3>
As it is a shortcode:
^ From the admin wp page->Posts/Pages->Add New or Edit, select HTML in the entry form and enter [galleryjb] 
^ Attach one or more images to the post or define a PostID attribute which has attachements i.e. [galleryjb postid=123] 
^ There are no mandatory attributes: it will show the attached images as a gallery if attachments are present in the current post or in postid, if postid as attribute is defined. 
^ Optional attributes are all those you can see in wp 3.0.4 or 3.1 of native gallery plus: 
^^ link: besides “file” (= images are linked to imagefile) and the default null string (= images are linked to the attachment’s permalink) already present in wp gallery, there is now “null” (images are not clickable/linkable) and “url” (images are linked to external URLs defined in Description). 
Please note that if you choose link=”url”?, the Description textbox in Media library needs to contain a url (http(s)..etc) and not a textual description. On the other hand, Description is not used by wp native [ gallery ] in any case. 
^^ target: boolean. if true linked objects open in a new/the same window, if false (default) in the same window 
^^ author: true (default) or false whether you allow this plugin’s author footer to be displayed or not (please, say yes).
<h3>Examples</h3>
[galleryjb link=”null”?] ==> Images are not clickable 
[galleryjb target=”true”?] ==> Images link to the attachment’s permalink and open up in a new page 
[galleryjb link=”url”?target=”true”?] ==> Images link to external URL defined in the Description textbox (in Media library). These URLs will open up in a new page. 
[galleryjb link=”url”?] ==> Images link to external urls defined in the Description textbox (in Media library). They will open up in the same page (as default)

Gallery Just Better

It's a tiny bit more flexible than wp native gallery. It finally allows non-linked images and images linking to external URLs.

James Irving-Swift

Add a mosaic from a flickr feed on your blog. All you have to do is put your flickr RSS feed in the admin page and then you can place the mosaic wherever you want on your site/blog.
The plugin displays thumbnails from your flickr feed and uses ‘fancybox’ to display a larger version of the image without having to leave your website.
When the images are enlarged, next and previous arrows can be used to cycle through the images.

Electric Studio flickr Mosaic

Add a mosaic from a flickr feed on your blog

Gallery Just Better vs Electric Studio flickr Mosaic