Executives at Wal-Mart kick off each weekend with a Saturday morning meeting in the auditorium of the company's Bentonville, Ark., campus. At the meeting, which is part pep rally, executives go over sales numbers, talk about merchandise, and have guests on occasion. It's not mandatory, but usually about 400 people attend. “The meetings help us keep in touch with our business,” says Sharon Weber, Wal-Mart spokeswoman. And the festivities open and close with the Wal-Mart cheer: Give me a W; Give me an A …