I found cutting and pasting snippets of code into my skype im very tedious as I'd always have to say which file and which line numbers. I wrote this small snippet to solve it

function! CopyWithLineNumbers() range
    redir @*
    sil echomsg "----------------------"
    sil echomsg expand("%")
    sil echomsg "----------------------"
    exec 'sil!' . a:firstline . ',' . a:lastline . '#'
    redir END

com! -range CopyWithLineNumbers <line1>,<line2>call CopyWithLineNumbers()

and when the CopyWithLineNumbers command is run on highlighted text you get in your paste buffer.

206 " Allows copy the buffer with line numbers included.
208 function! CopyWithLineNumbers() range
209     redir @*
210     sil echomsg "----------------------"
211     sil echomsg expand("%")
212     sil echomsg "----------------------"
213     exec 'sil!' . a:firstline . ',' . a:lastline . '#'
214     redir END
215 endf
217 com! -range CopyWithLineNumbers <line1>,<line2>call CopyWithLineNumbers()

I dedicate this blog post to my colleagues who keep insisting on sending me code snippets without telling me the file or line number it comes from