Long Gâyatrî Mantra from http://wahiduddin.net/mantra/gayatri.htm

Om Bhu Om Bhuvaha Om Swaha
Om Maha Om Janaha Om Tapaha Om Satyam

Om Tat Savitur Varetnyum
Bhargo Devasya Dhimahi
Dhiyo Yonah Prachodayat

Om Aapjyothi
Raso Amtritam
Brahma
Bhur Bhuvaha Swarom

( translation )