Hi all i will be in Cusco from the middle of july and was wondering about doing a trip up to the Amazon from there. Is it possible? is it expensive? can anyone recommend it?
I was also considering going straight to Bolivia from there and then doing trip from Northern Argentina. Would that be possible, and if so is it likely to be more expensive?
Any help would be greatly appreciated
Many thanks
Martin
Hello Marty!
Starting at 3,700 USD 
for a trip up the Amazon...(tour style)
http://www.uwalumni.com/travel/2005/amazon2.html
or whitewater rafting and kayaking...
http://away.com/tripideas/cusco-cusco-whitewater-kayaking-300276.html
I hope this helps a little.
Sounds very adventurous!!
I hope you have an excellent time! 
All you've gotta do is get from Cusco to IQUITOS, Peru. Check out the links that Cupcake posted.
The only way of getting form Cusco to Iquitos is vis plane. You could get a bus or fly from Cusco, bus not sure, flight is 50 english pounds. The flight to Iquitos is 80 English,
I was well lucky, i was asked to go on a later flight form cusco to lima, and they gave us a free return from lima to iquitos! all for 50 quid! You cannot fly direct fomr cusco to iquitos.
Tarik