[re-shared from the web]
ChemSpider is a free access service providing a structure centric community for chemists. Providing access to millions of chemical structures and integration to a multitude of other online services, ChemSpider is the richest single source of structure-based chemistry information.[http://www.chemspider.com/]
If you are an iPhone user, or use a phone with a browser, I suggest you point it to the new ChemSpider Mobile at http://cs.m.chemspider.com . There you’ll see a simple interface, shown below, that allows you to search across our database of almost 25 million chemical entities based on chemical name systematic, trivial or trade, registry number etc and retrieve a list of intrinsic properties, a list of predicted properties, a list of associated identifiers, with links to Wikipedia if available, and a Google based search for the chemical based, for now, on the associated InChIKey.
We are also working on providing access to ChemSpider SyntheticPages in the same way and the first screen shot is shown at the bottom. Things are always changing and, I believe, for the better.