While capturing you can change your video and slide sources. The selected video and slide sources are highlighted in blue. Just click on the name of another source to start capturing other sources.
However there is a limitation while recording. The first selected video source will determine the output resolution of the video. In case you start you recording with a 320x240 webcam and switch later to a HD resolution camera source, the resulting resolution will be 320x240 pixels.
You can see the output resolution in the top right corner of your video or slide source.
In case you have purchased a Presentations 2Go Pro license all video devices will be available as Video and Slide source. The Lite edition only allows internal screen as Slide sources.