Don't know if it's the cheapest, but the
easiest way is the Official Bus of Disneyland...The Airport Bus. You can't miss 'em. They are decorated with all the Disney characters.
$14 one-way, something like $25 round-trip.
www.airportbus.com
Metrolink...I don't know the price, but it stops at Anaheim Stadium. There may be a bus from there to the Disneyland Convention Center area.
[This message has been edited by PremEx (edited 03-12-2003).]