Let your audience classify or categorize concepts by dimensions / properties determined by you! Dual axis is a two dimensional rating poll, of sorts.
Activate the creative power of your audience through free association using the unique "Word cloud" content. Anything your audience can come up with is displayed in a 3D animated word could on the screen. An awsome brain storming tool.
The traditional likert scale poll is an ideal way to get instant feedback from the audience and to allow their grading of for example services or activities.