One year after it launched, Google has finally upgraded its instant messaging client, Google Talk, with some slick file-sharing functionality and voicemail capabilities, which could help increase Google's market share.

The instant messaging wars have gotten hot again, now that the software includes the ability to make VOIP calls to regular phone lines. As Om Malik notes in his comments on the news, this upgrade is "part of the trend of some demographics turning to IM to manage their online communications instead of email." But Google's young service has lagged far behind the competition in signing up users. That's a rare misstep for the search giant, which is usually good at getting the young crowd to try out its products.

Today's upgrade, however, could give Google a boost. An effusive in-house bloggger at Google describes how the file-sharing works: "You can drag and drop one or more files directly onto a chat window. As soon as your friend clicks 'Accept', the bits will start flowing." And it works even better for photos: "When you drop up to 10 photos on Google Talk, smaller previews automatically appear right inside the chat window, so you can chat about them right away."

While file-sharing has long been a feature in AIM and other IM software, Google's version is easeir to use and, importantly, well-integrated with its popular Gmail email service which should drive adoption.