It's easy to post photos of pictures already in the gallery without having to do a search on the URL, etc if you use
Mozilla Firebird as your browser. It's a stand-alone browser and has tabbed browsing, along with customizable skins and drag/drop bookmarks.
To find the file location of any photo do the following...
1. Open Mozilla Firebird
2. Go to the page where the photo is
3. R-click on the photo
4. Choose "Properties" in the dropdown menu
5. Under Image Location, highlight the URL that's listed under "Location"
Other info is displayed as well (height, width, size of file, resolution)
6. Insert in your YaBB tags