1. Photos, ask potential customers if they would e-mail a photo with their testimonial. This technique will give your testimonials more credibility.
2. Scanned Signatures, many online testimonials have text signatures. You could have people mail their written signature, scan it, and upload it with their testimonial. People will feel the testimonial is more authorized.
3. Audio Recording, recording testimonials with a mobile phone, on your answering machine, or voice mail. Then convert the recording into a digital audio file and upload it to your web site.
4. Postcards, if you have customers mail you their testimonial on a postcard, scan it and upload it to your web site. This will give people proof that the testimonial isn't fraud because it will have a post mark on it.