Windows Live MessengerEarlier this month, Microsoft announced it would send Windows Live Messenger to the great scrapheap in the sky in a bid to migrate existing users to Skype (which it acquired for $US8.5 billion last year). In its heyday, Windows Live Messenger had over 300 million active users per month. Despite competition from Yahoo and Google, it remains one of the world's most popular instant-messaging programs. By contrast, Skype's IM tool currently has a user base of around half its size. Will Microsoft's gamble pay off?