Oh goodness, yes. I'm alone almost all the time, so it's nice to hear a voice, even if it's just mine. I tend to plan things or think out loud a lot when it's just me. Hell, sometimes I can't help but think out loud at school or in public, though I keep my voice low. Most of that is just things like 'oh, did I forget something?' and such, though. People IRL think I'm crazy anyway, so what does it really matter?
I originally joined Twitter so I could talk to myself via typing