What an amazing idea! Why, if someone had come up with this idea, say, a year ago, why, they could be rich right now!

Splitting dinner checks can cause a splitting headache, even when the diners are a math-oriented data miner, a database security specialist and an expert in networked games.

Fed up with haggling over shared debts, Carnegie Mellon University computer science graduate students Shashank Pandit, Amit Manjhi and Ashwin Bharambe three years ago created Buxfer, short for ''bucks transfer.'' The social-networking site with a personal-finance focus allows users to form groups of friends or housemates and track who owes what for utility bills, dinner tabs, day trips and other shared expenses.

No more haggling: Grad student Web site tracks shared expenses