'''Dolphin''' has a ability to rename multiple files by numbering them, though the functionality is currently limited and only useful in certain situations. One useful application would be renaming a set of photos.
Select the files you wish to rename, then right-click on one of them and select <menuchoice>Rename...</menuchoice> (keyboard shortcut <keycap>F2</keycap>). You will be presented with a dialogue where you may specify what you want the files to be named.
The '#' symbol anywhere within the file name will be replaced with a number, starting with '1' for the first file and continuing up for each file after that.