http://www.bts.gov/xml/ontimesummary...yDepatures.xml
A cool resource. Flight information dates to 1995, and is usually delayed about 2 months from the present. Currently displays data up to 5/08.
A/C registrations are displayed as the aircraft's N-number, and CO internal ship numbers are comprised of the last three numbers of this registration, so N33103 would be ship #103, a 752. If you have any questions regarding fleet numbers and aircraft registrations, the FAQ probably covers it.