ANA is a Japanese airline which is part of the Star Alliance. Meaning, you can use their miles on any Star Alliance carrier, e.g. United, Continental, Air Canada, US Airways, Lufthansa, Swiss etc. etc.
They also have non-alliance partners, e.g. Virgin Atlantic, Jet Airways, Qatar.
Since their
award chart is distance based (dependent on actual miles you fly on the award as opposed to regions) in some instances the value is very good.
But beware they charge a heavy fuel surcharge (extra $$$ you'll pay on your free ticket) so unless you are redeeming on a US carrier or Virgin Atlantic its usually not worth it.
As with all airlines, the transfers can be done from the SPG and Amex MR sites respectively.