I don't plug products all that often, but if you hate installing instant messaging clients, check out meebo. You can use all kinds of networks separately or at once, and you can even add a little widget to your blog (this blog! our blog!) so readers can IM you in real time. Of course, now that I have unlimited IM on my phone, I can't pull myself away from its oh-so-accessible glow. This is really helpful in libraries, at work, and on friends' computers.