Many of the locations featured in the movie are actual locations found in Dallas Texas (e.g., the Texas Club, Reunion Arena, Dallas City Hall.) However, the stainless steel building of the "Moore Company" in the movie is actually the Dallas Federal Reserve Bank (K-11) which is located in the cultural district of Dallas.
During filming in 2002, 'Matthew Perry' spent some time in rehab due to an addiction to prescription painkillers. Production was slowed, but the filmmakers focused on filming scenes without Perry in them during his absence.
When Sara originally makes up the "contract" between herself and Joe, she does not sign her name on the bottom, writing only "One Million Dollars". Later on when Joe shows her the contract, her name is signed on the bottom.