Recently, I am looking and testing free (I am a poor college student) and portable (can go with me on my trip) teleconferencing solutions to discuss research topics with talents around the world. Finally, I figured out that Xournal + Skype Talk Screen on Ubuntu Linux could be a good choice.
Well, everyone loves Linux, and Ubuntu. Everything just works out of box on my Dell Mini 10, except the embedded microphone. Doesn't matter. I can plug an external mic to the jack.
Xournal and Wacom pen tablet
When discussing, I need to show my scratch to my friends as we are talking in front of a chalkboard. I tried tablet PC. Ah, too many drawbacks on other aspects. So I use a pen tablet. I did some test, and after few practices, I can write and draw well.
There is an open source software called Xournal on Linux. Xournal can digitize the trace of your mouse or tablet pen - just like taking notes on traditional paper. You can install it via apt-get or Synaptic. It works better than Windows Journal or One Note.
I used a bluetooth Wacom tablet. You need to do small bug-fixing to make it work. Here is the information https://help.ubuntu.com/community/WacomGraphireBluetooth
Skype, and Talk Screen
Google Talk, based on XMPP protocol, works fine on Ubuntu Linux, via Empathy or Pidgin, to support video and audio chatting. But, I can't share the screen and therefore cannot show my scratches on the tablet to my friends.
Luckily, Skype released a beta version with screen sharing function, aka Talk screen, in early 2010. So I download it (make sure you download at least Skype 184.108.40.206) and install it. Bingo!
Here are some pictures showing how to so. First call your friend. After he/she picks up, find the blue button with a camera logo in the chat window.
Then a frame will pop up to let you select the part of the screen you wanna share. U can move it around. I will place it to the center of my Xournal window. Once you are done, click "Start screen sharing" button at the bottom of the frame.