Lagrange points operate between Earth and Sun as well... which can be
put to good use.


http://www.cds.caltech.edu/~shane/pa..._ross_2001.pdf

More popularized versions of the same information;

http://map.gsfc.nasa.gov/m_mm/ob_techorbit1.html
http://plus.maths.org/issue36/features/dartnell/
http://map.gsfc.nasa.gov/m_mm/ob_techorbit.html