This is not the first time it has happened and I bit not the last. One part of my role is going to events to demonstrate the technology. As part of the preparation I was always ask the event organisers to ensure we have at least have a wireless internet connection. To be fair they always do have an internet connection. The problem being that it is not always as good as you would have hoped for.
I was at an event last friday where said internet access was not particularly reliable and so I had to resort to my mobile to do the demo over 3g. As I said this has happened before as highlighted out in Mark's blog.
If you don't believe it is do able check out this video, which had Brett, I and Junners on a three way video call while Brett speed through the countryside on a train (Brett recorded this on a his mobile so apologies for the quality and Brett's dusty screen).
So I hear you ask what is the point of this rambling - well it is certainly not encouraging you to do this - the cost (depending on your data plan) could be career threatening in the current financial situation. It is more about demonstrating the ingenuity that Communicator /OCS uses to ensure calls can be completed over poor links. Ideally we would love to have great big fat pipes but in real life this is not always the case and when push comes to shove and you need to do that vital call and share info some technologies will not even try, whereas we can.
To read more on how we do this check this doc (it is from OCS 2007 and more has been done to make this even better in R2)