A chance to see and be seen with Leonardo DiCaprio in Los Angeles. Or eat clam chowder with Ben Affleck in Boston. Or dine with Ricky Martin in Miami. These aren't necessarily fantasies for those with deep, charitable pockets.

These celebs — as well as Sarah Jessica Parker and Benjamin Bratt — will auction dinner in their company for charities they have chosen individually. The bidding, which was to begin Thursday, concludes on Oct. 3. It is being held on a Web site run by eBay, accessible through Godiva.com, the sponsor of the fund-raiser.

The winning bidder can bring seven friends to the dinner, each of which will be created by a well-known chef and topped off by a new truffle from Godiva.