Here's yet another reason I wish I had an iPhone rather than another brand "smartphone" -- The American Chemical Society (ACS) just launched an iPhone application for its Molecule of the Week (MOTW). It's also available on the iPod Touch and the just-released iPad.If you're not familiar with MOTW, it's a quiz that gives you a clue about a molecule and you must guess which molecule it is. According to the ACS website, "Many molecules are suggested by chemists and chemistry enthusiasts. Every structure is reviewed by a scientist and displayed in 3-D and flat images with a brief description.Each week’s molecule also links to a sample record from the CAS Registry, which is searched using SciFinder. Each record displays the registry number, index name and synonyms, bibliographic information, and more."