Many CMS' don't offer a way to manage picture galleries easily, and neither does symphony out of the box. But, after playing with symphony some, I decided that I liked it and the next project I would do would be with symphony.

So I created a plugin (in symphony: extension) that allows you to upload multiple files, and create entries (in this example, gallery items, or rows in the database, etc) to allow you to accomplish this easily.

You can download it at my Github repo.