iSkoot, which providers a plug-in software that lets users access Skype and other similar internet-based calling services using mobile phones, has raised a second round of $7 million led by Charles River Ventures. Three previous investors—Khosla Ventures, ZG Ventures, and Jesselson Capital Corp.—took part in the new round. The company raised $6.2 million in its first round. The company will use the funds to expand its sales, R&D and marketing efforts. iSkoot has established partnerships with mobile operator 3 and Skype, which have joined to launch a Skype-to-mobile service. iSkoot software will come preloaded on certain phones, including Nokia and Sony Ericsson handsets.  Press release