All above,
Many thanks for your replies. There are many options available; I trialled several
except the one you suggested Jofm5 (will do ASAP). Of those I've tried (Adobe Connect Pro, Adobe Connect, Voxwire, Webex etc) GoToMeeting is the best. I need to broadcast video clips so they'll have to be embedded in presentations (swf?). Or is web-based video an option?
Final - your point about using Skype is a good one. I trialled a presentation this morning with a friend in Melbourne (I'm in the UK) and the thing that let it down was the audio; we switched to Skype and it worked OK. The thing is, I am adding this to the services I offer as part of my business. When setting up a presentation, I want to make sure I've let them know what they need; I think I'll suggest they keep Skype up should the GoToMeeting audio fail.