hi Issa,
I normally do it on my mobile (I have an Android phone - any Android device will do, as well as Windows Mobile 5 & 6 devices, Blackberries and other Java based mobile phones)... I then connect the GS-911, make the connection to my phone, select the engine, select the realtime values (at this point you will see them) - then select options/menu -> log values (or start logging or something like that...) once done, I normally just send them to the server (once uploaded you get a link where you can view or download them as CSV) ...then I put Excel to god use...
alternatively I know of a number of people who use there little netbooks to do this... you just need to configure the netbook itself that is does not go to sleep when you close the lid) - then pop it into a backpack and off you go...
best,
Stephan