I can't believe I hadn't seen this amazing stuff before:
http://retrographicdesign.com/hand-lettering-by-david-kindersley-1969/

hhp

Whod've thought the lowliest of office supplies could play into this:
http://www.urtd.net/fonts/clip

hhp

A rather pretty “M” that might be interesting in this context,
https://www.facebook.com/RachelYallopCalligraphyLettering/posts/58828063...

Totally chiroliminographic - thanks Nina.
Now help me find a shorter term. :-)

hhp

And another paperclip font!
http://www.myfonts.com/fonts/letterbox/morice-round/

hhp

Hmmm...
http://www.myfonts.com/fonts/fonthead/shoe-string/

hhp

1918, I believe

...my line version of google.

Alexander Calder

http://vimeo.com/5233789

Von Glitschka "Continuous Line Illustration" style.
Some examples:
http://www.vonglitschka.com/2010/05/06/tasty-visual-recipes/
http://www.vonglitschka.com/2011/11/28/fly/
http://www.vonglitschka.com/2012/08/07/att-linears/
http://www.vonglitschka.com/2010/02/12/linear-personality/
http://www.vonglitschka.com/2009/09/04/continuous-line-icons/
http://www.vonglitschka.com/2012/03/13/driving-the-line/
http://www.vonglitschka.com/2011/03/18/march-madness/

And Step by Step Tutorial (text file plus images for each step):
http://www.illustrationclass.com/downloads/raw_tuts/Continuous_Line_Illu...

Does this count?
http://www.flickr.com/photos/lee20sk/8945763391

Great stuff people.

Some more candidates here:
http://dribbble.com/JockintheBox
Like: http://dribbble.com/shots/960623-1968-Olympics-meets-Slab-serif-II?list=...

hhp

This one is awesome!
http://fontstruct.com/fontstructions/show/827761

Yes, interesting twist!

hhp

Another example:
https://twitter.com/LloydNeel/status/452374284938133504/photo/1

hhp

And I wonder if this also qualifies:
http://www.rymaneco.co.uk/

hhp