<p>Is there a web service of some sort (or any other way) to pull a current time zone settings for a (US) city. For the parts of the country that don't follow the Daylight Saving Time and basically jump timezones when everyone else is switching summer/winter time... I don't fancy creating own database of the places that don't follow DST. Is there a way to pull this data on demand? </p>

<p>I need this for the database server (not for client workstations) - there entities stored in the database that have City, State as properties. I need know current timezone for these entities at any moment of time.</p>

earthtools.org provides a free web service to get the time zone from a city here:
http://www.earthtools.org/webservices.htm#timezone
You just pass in the long/lat values like this: (This is for New York)
http://www.earthtools.org/timezone-1.1/40.71417/-74.00639
EDIT:
It seems like earthtools has been shut down. A good alternative (That did not exist in 2008 when this question was answered) is the Google Time Zone API. To use it you must first
activate the Time Zone API
on your account. It is free if you stay below these limits:
2500 requests per 24 hour period.
5 requests per second.
The documentation
is available on Google Developers.