If you are really charming, you may be able to get customers to offer glowing testimonials on camera.
For the sake of authenticity, treat the shoot as an interview, and ask about what their experience was like when working with you or using your product. Cut one or more testimonial videos together to make a testimonial mashup, or publish them individually.
These will be dramatically more effective than boring plain-text testimonials.
Excerpt from Innovative Marketing Resources.