One of my most favorites:
http://www.flickr.com/photos/monikagermann/5533430851

hhp

http://lauraworthingtontype.com/

My favorites:

Michael Clark
http://www.typerror.com/

Stephen Rapp
http://stephenrapp.com/

Charles Borges de Oliveira
http://www.borgeslettering.com/

Ian Brignell
http://www.ianbrignell.com/

Just a clarification — I think all of these artists (except for Mónika) would more likely call themselves hand-letterers than calligraphers. Hand-lettering and type design have a lot in common, whereas calligraphy is a whole different skill. Of course, each of these three often imitates the others.

Jordan Jelev

Thanks Pablo! That made my day!! :)

Some more doing calligraphy and lettering:
Jill Bell
Nick Cooke
Seb Lester
Jessica Hische

Iskra Johnson
http://www.iskradesign.com/

Keith Morris
http://www.keithmorris.com.au/

Gabriel M. Meave
http://www.meave.org/