A psychologist plans to sweeten people's dreams using their smartphones.
Professor Richard Wiseman expects thousands of people to take part in an experiment in manipulating dreams.
Participants will download a specially designed iPhone app that turns their phone in to a dream factory. Placed on the bed, the phone can detect when a sleeper is not moving, which signifies the onset of dreaming.
It then plays a carefully crafted "soundscape" designed to evoke pleasant scenes such as walking in woods, or lying on a beach.
The idea is that this will influence dreaming, causing dreamers to conjure up situations and experiences inspired by the sounds they are hearing.
At the end of the dream the app sounds a gentle alarm to wake the dreamer, who submits a brief description of the dream to a "dream catcher" database.
Prof Wiseman, from the University of Hertfordshire, who is best known for his work on the paranormal, said: "Getting a good night's sleep and having pleasant dreams boosts people's productivity, and is essential for their psychological and physical well being. Despite this, we know very little about how to influence dreams. This experiment aims to change that."
As many as 10,000 people are expected to take part in the mass-participation study, launched at the Edinburgh International Science Festival.
Prof Wiseman teamed up with app developers YUZA, which created the "Dream:ON" software. Participants will be encouraged to share their dreams via Facebook and Twitter.
A national survey conducted for the experiment found that 21% of respondents had trouble sleeping and 15% suffered from unpleasant dreams.
Prof Wiseman said depressed people dreamed far more than others, and often had negative dreams. "Perhaps improving their dreams might help them," he added.
The "Dream:ON" app can be downloaded for free from iTunes or via the project site, http://dreamonapp.com.
Throughout history, dreams have been associated with creative thinking.
Here are some examples of creative dreams:
"Those who curl up in the foetus position are described as tough on the outside but sensitive at heart. They may be shy when they first meet somebody, but soon relax. The foetus is the most common sleeping position, with women more likely to adopt this position than men."
"Lying on your back with both arms up around the pillow. These sleepers make good friends because they are always ready to listen to others, and offer help when needed. They generally don't like to be the centre of attention."
"Lying on your front with your hands around the pillow, and your head turned to one side. Often gregarious and brash people, but can be nervy and thin-skinned underneath, and don't like criticism, or extreme situations."
"Lying on your back with both arms pinned to your sides. People who sleep in this position are generally quiet and reserved. They don't like a fuss, but set themselves and others high standards."
"People who sleep on their side with both arms out in front are said to have an open nature, but can be suspicious, cynical. They are slow to make up their minds, but once they have taken a decision, they are unlikely ever to change it."
"Lying on your side with both arms down by your side. These sleepers are easy going, social people who like being part of the in-crowd, and who are trusting of strangers. However, they may be gullible."