Is there a shortcut/command to copy the title of a webpage in Vimperator?
I don't think there's a key for it built in.
Defining a yanktitle command
You can define the following command to do it:
:command! yanktitle :js util.copyToClipboard(buffer.title)
Or if you prefer, bind a key to the JS command, eg. xy
:nmap xy :js util.copyToClipboard(buffer.title)<CR>
A related command: copy link description
A related command is the extended hint command ;Y, which copies the description of a link
:command! yanktitle js dactyl.clipboardWrite(buffer.title) :map -b xy -js dactyl.clipboardWrite(buffer.title)