Getting on the bandwagon, how could I not mention Google's new GoogleTalk
? Not only taking on MSN Messenger and other Windows-based messaging applications, but also with built-in VOIP (voice over IP), this could be Skype-killer as much as a Microsoft-killer (well, competitor, anyway, if you don't enjoy over-excited hype).
For a long, detailed review see the Download Squad
, then Mac-users see how GoogleTalk can talk to you
and then, to top it all off, start thinking about this as part of a Web-based OS a la Jason Kottke
An interesting day in the datastream, alright!