[OSX-Users] battery packs for iphones

[Neil Broderick]

Hi,
with regards extending the battery lifetime of the iphone has anyone  
tried
any of the external battery packs that you can buy? Ideally I want to  
be able
to record a 6 or 7 hour GPS track when going on a long ride and  
currently
the iphone battery dies after about 3 hours.

Also does anyone know if it is possible to get the raw timing data out  
of
the GPS chip? Being slightly deranged I would love to know the time to
nanosecond accuracy and since there is a GPS chip in my phone that
information is there and I just have to figure out how to get it.

cheers,
Neil