Hi Laura:
Great question! I work with a number of clients in "traditional" businesses such financial services and utility companies that are....shall we say....'digitally challenged." For these clients, nothing can really replace "analog" technologies such as picking up the telephone or having a face-to-face meeting.
But...since face-to-face is not always possible, especially for the mobile inclined among us, we do a lot of teleconferences. Two services I have used for this (but there are many many others,) are ureach and Gotomeeting. Gotomeeting has a nice record feature to dump all audio and screen activity into a file for later use. As you mention Open Source, there are probably a number of freely available tools which do something similar. I'm personally partial to Gotomeeting because:
1)It is really fast, and allows for almost seamless handoff off of keyboard and mouse among large numbers of participants. Great for demonstrations, troubleshooting, slides, etc. When working with most mid-to-large companies, 95+% of the install base uses Microsoft Windows of one flavor or another, so it is easy for them to quickly install and join a meeting
2)It scales well to 15 participants, or more if screens are shared
3)Integrates well with Lotus Notes and Microsoft Outlook, which have large client install bases -- which I find to be very important in working with larger companies. The ability to "get on their calendar" is huge!
4)Even the most non-technical user can click the meeting link, install the software, and be in the meeting in minutes
5)Each meeting created with Gotomeeting automatically creates a conference phone number that can be used
Another thing we often do, is take either captured Gotomeeting sessions, or recorded audio from Telecasts and package them as mp3 with a url. We can then send these to clients and just say "click here when you want a refresher, and call us if you have any questions."
(In case anyone is wondering, I do not work for, with, or receive any paid compensation for endorsing Gotomeeting. I just do so because it works! :-)
Ureach has a number of interesting features as well, and is very user-friendly for non-technical people.
As for keeping in touch, I generally try for two 1-hour phone meetings per week (at a minimum) per client.
Regarding IM, I personally stay well away from it. Not only are there a number of legal issues with some larger companies to consider, but it can be an interruptive productivity drain.
Then of course, there's Skype and Net2phone for calling anyone, anywhere, anytime. I find that Net2phone has a bit better sound quality (they've been around longer than Skype,) but Skype has a lot of great voice recording options.
I have yet to personally try setting up video-enabled chat with non-technical users.
While we're on this great subject, I would be interested to get other Biznik perspective on effectively managing multiple channels of communication such as voice, IM, email, snail mail,etc. This is always a challenge for me anyway, especially in larger accounts where they like to use all of the methods all the time!
Best regards,
-Corbin Links Linksbusinessgroup.com