Rumor has it that Microsoft Corp wants a stake in Audible Inc. The closely held company, founded by former Novell VP Andy Huffman, writer Don Katz and former Macromedia CEO Timothy Mott, sells a $199 portable player for RealAudio files which can be downloaded from the internet. Audible also retails content for these MobilePlayer devices. Its wares include talking books, news from CNBC and the Economist and National Public Radio programs like Garrison Keillor’s A Prairie Home Companion. While the MobilePlayer is an obvious target platform for Microsoft’s Windows CE operating system, the Redmond software company has yet to find a strong model for its ventures into content provision.