Another technique I’ve used is zooming with a friend. She just moved from my the Bay Area to Southern California and now she telecommutes. We’ve both found it useful to zoom (video conferencing like Skype of Facebook) at scheduled times.
We check in with what we are going to do over the next few hours, parallel work and then check out about how it went. We also talk about what we are going to do over the next few days.
Not only does it help with my productivity and loneliness, but it helps me to stay connected with my friend after she moved away.