There are many sources out there for getting global time and timezone information online. Now there's an service getting local time anywhere in the world from the small startup WorldTimeEngine, a service which is both a mashup as well as an API. Their basic web site centers around a search box where users can search on names and geographic locations like "india" or "10 downing street, london" or "51.50, -0.126236". The result of the search is itself a mashup that shows a the location plotted on a Google Map along with a variety of time-related data like timezone, UTC/GMT offser, DST, and geographic coordinates. The example below is from our mashup profile:
Their RESTful web service API returns the local time in an XML data structure based latitude and longitude coordinates. You can view more details in our WorldTimeEngine API profile. The API is available for commercial use via a subscription model at £72 per year (and it's one of the first APIs we've seen where you can buy usage on the spot using Google Checkout).