I often remind my students that mistakes are a good thing.
Identifying a mistake and thinking about changes and improvement becomes a new skill. I think it is important to discuss this process every time a mistake is made; the repetition eventually helps students identify the importance of making mistakes.
Learning this skill gives students experience that helps in real-world problem solving.
I like to model the problem solving process when difficult questions come up in our communication technology program. There are many complex systems that students help build, maintain and improve. New technologies constantly pop up that influence/instigate problem solving.
My favorite use of technology to help students discuss mistakes and improvements in their work are student built wiki pages for public feedback. Students comment on each others work with replies on wiki entries. Feedback helps improve their work.
Diana Laufenberg teaches in Philadelphia and spoke at TED about her experiences in current technology and authentic experiential learning and allowance for failure. Here is the video:
The link jumps to a specific time, but feel free to watch the whole talk.