From the Wordpress Extend Page :)
WPG2 is a Wordpress Plug-in that embeds Gallery2 within Wordpress to share photos, videos and any other Gallery2 content seamlessly into the Wordpress Sidebar and Blog entries.
* G2Image insertion tool in your Edit Toolbar to help you select one or more Gallery 2 Images, Videos, Albums (displays the Album Highlight Image) in your Blog Posts or Wordpress Pages
* Random, Recent, Daily, Weekly, Popular Images and/or Albums can be displayed as widgets in the Wordpress Sidebar
* Single Signon of Wordpress Users into Gallery2, with the ability to restrict Gallery2 Sign on through Wordpress User Roles and Capabilities
* Display your Gallery2 Page(s) from within the automatically created Wordpress Page.
* Add Lightbox Effects for your Gallery2 Images