fi aman Allah is very much common among religious minded arabs too in particular countries such as 'Iraq. another one among jordanians, lebanese sunnis, palestinians is "Allah ma'ak" alwida is not used, it is very uncommon the reason being it is used for someone who is going to leave you(die?/or at least for a long time), not liked very much I have rarely seen arabs use alwidaa, I myself dislike it. The only place in the arab world where I heard it being used is in in Japanese cartoons that are dubbed into arabic such as "captain majid/georgy etc etc" cute little weekly cartoon series I grew up with in the Persian Gulf, especially in Iran. All children in the Gulf have seen these cartoons, including me. All the way from 'Iraq down to 'Oman. Not sure about Yemen, but recently all the Yemeni kids (from Ibb, south yemen) who I encourted in the Gulf loved these cartoons and immitated them. In those cartoons they used to say to eachother "al wadaa'" "wadaa'n" when another cartoon character was leaving forever.