Nolan Chou

Sometimes we forgot change our file to a available name. So the plugin can help you auto change your upload file. 
I will add a filetype option of setting in next version. 
And a rename popup before the file upload if you change setting in future, default value is post_name.

wp_upload_rename

Change upload filename to random characters / random numbers / date / other by yourself.

Cheetaho

[Tattoo Images] is a WordPress plugin that let’s you pick pictures from <a href="http://tattmight.com/" rel="nofollow ugc">Tattmight.com</a> and insert them with just a click anywhere on your blog. The images are safe to use, linking back to the source is required.

Tattoo Images

[Tattoo Images] is a WordPress plugin that let's you pick pictures from Tattmight.com and insert them with just a click anywhere on your blog.

wp_upload_rename vs Tattoo Images