http://news.bbc.co.uk/2/hi/americas/7640183.stm

Huge new prime number discovered
Mathematicians in California could be in line for a $100,000 prize (£54,000) for finding a new prime number which has 13 million digits.

Prime numbers can be divided only by themselves and one.

The prize was set up by the Electronic Frontier Foundation to promote co-operative computing on the Internet.

The team from the University of California at Los Angeles (UCLA) found the new number by linking 75 computers and harnessing their unused power.

This enabled them to perform the enormous number of calculations needed to find and verify a new prime.


Now we're looking for the next one, despite the odds
Edson Smith
UCLA

Thousands of people around the world linked the powers of their personal computers in the search for a higher "Mersenne" prime number - named after 17th-Century French mathematician Marin Mersenne.

Mersenne primes are expressed as two to the power of P, minus one - with P being itself a prime number.

Edson Smith, the leader of the winning UCLA team, told the Associated Press news agency: "We're delighted. Now we're looking for the next one, despite the odds."

---

team starfire world boinc http://www.teamstarfire.net

AFAIK the biggest use of large primes is cryptography.

OTOH, mathematicians have always been able to put me to sleep once they depart from things useful in general physics.