\setuparranging question

[Gerben Wierda <Sherlock@rna.nl>]

How can I get the following arrangement:

2 A5 pages printed on one landscape A4 page
Order:
	-1 0
	1 2
	3 4
	5 6
	7 8
or in other words, no order which makes it ready for cutting/folding 
but just two A5 pages per A4 landscape in normal order, the way you 
would get it when you copy a book on A4 landscape.

(Even better would be to have alternate A4 printed pages upside down so 
you can print doublesided and then bind it so you can flip the document 
without having to turn the printout.)

Thanks,

G