Here's a list of US Airlines WAP Sites that I have:

AA - http://www.aa2go.com
DL - http://mobile.delta.com
CO - http://wap.continental.com
NW - http://wireless.nwa.com
Alask - http://wireless.alaskaair.com
UA - http://www.ua2go.com/

I also lifted a few Intl sites from the Best WAP Sites thread
BA - http://wap.britishairways.com
LH - http://wap.lufthasa.com