Visualisers: pros and cons of connecting USB/separate power, etc.
Can anyone give me an idea of the pros and cons of the various ways you can connect visualisers? I see some connect and take power over USB, and some seem to have separate power and connect through the VGA port. We would be using them with SMARTboards. Power sockets are always an issue here, and I am tempted by the idea of USB connection. But does that take a lot of power from the laptop, meaning that it grinds to a halt..?? Also, how do you connect via VGA when the SMARTboard is attached to that on the laptop? Sorry if I am being very dense, but I have no experience of these and need help from all you experts out there...flatter, flatter... I need to avoid making an expensive mistake!