I am interested in any writings on Agatha Christie's time in Luxor
Egypt while she was writing Death on the Nile.  Are there any articles
written by her, or about her while she was there, did she agree to any
interviews on life in Egypt? The book "Come Tell Me How You Live"
written by her does not have any information in it, pertaining to
Egypt. I am interested in her observations of the place, the people,
history of the Winter Palace Hotel especially. She lived in the hotel
while she was writing the book. I want to describe Luxor from her
point of view while she was there, why she loved it so much.

I have not read this, so do not know whether it will be useful
Agatha Christie and Archaeology  
Charlotte Trumpler (Editor) 
471 pages (12 November, 2001) 
British Museum Press; ISBN: 0714111481
“This book, which accompanies a new international exhibition, should
appeal to fans of crime novels, archaeology, the Orient and biography
alike. Using sumptuous colour photographic illustration, this book
sets out to recreate Agatha Christie's life in the Orient, with
reference to both her novels and her personal diaries. Using artefacts
and personal photographs from archaeological excavation, and her own
accounts of travel and her relationship with archaeologist Max
Mallowan, this book paints an unusual and striking picture of her as
an intellectual, author and explorer.
Available on amazon.co.uk for  £19.99, but not on amazon.com”
http://www.amazon.co.uk/exec/obidos/ASIN/0714111481/ref=ase_wwwfathomcom-21/202-8281524-0191054

There is a good chance that the book mentioned by tehuti-ga has some
useful information.  A review of the exhibition upon which the book is
based states: "Agatha Christie as the exhibition revealed was
influenced by time and place.  She was also a keen photographer
shooting pictures with her Leica camera from the balcony of her suite
at the Winter Palace in Luxor."

"Dark emerald - Agatha Christie in Shiraz", by Cyrus Khadivar
(November 23, 2001)
The Iranian
http://www.iranian.com/CyrusKadivar/2001/November/Agatha/

I saw the exhibition about a year ago; I recall that it contained
information about her play "Akhenaton", which I assume relates to her
time in Luxor.

You might also try Henrietta McCall's 'Life of Max Mallowan' (208p, 8
b/w pls, British Museum Press 2001, ISBN 071411149X, Hardback).
Mallowan was the archaeologist who married Christie in later life. The
book includes extracts from the personal letters of Max and Agatha.