In a rare move, Google (GOOG) has placed an ad on its home page. It's for the company's Nexus 7 tablet, which has sold well thus far, but is expected to receive fresh competition soon from a new Kindle Fire and the iPad Mini. Also, it was just yesterday that Lenovo (LNVGY.PK) launched a new Android tablet. At $300, the IdeaPad A2109 is more costly than the Nexus 7, but it also offers a 9" display. Both devices use Nvidia's (NVDA) Tegra 3 processor.