NASS (North American Sundial Society) Comprehensive American site devoted to Dialing.
UK Sundial site;
Comprehensive site from the folks that brought you Stonehenge.
Another site in the UK, this one by
Mike Shaw; Many interesting instruments and facts, including some heliochronometer history.
The solstice project;
Great site devoted to Chaco canyon and the Anastazi.
The Math and Geometry behind
the analemma, excellent site with many visual aids and animations.
The University of
California Observatories' very comprehensive page on time scales, With links.
And now for something completly different ...
A site devoted to the care and feeding of olde English (and other) sports cars with the SU carburetor.
The Sundial Sculptures of John Carmichael,---
and another page from John about Stained glass sundials,
with many examples of these beautiful and historic dials.
Pinhole astronomy
and some reflections on the history of the science.