I launched now 3 Balloons with an Arduino Mega one to 35km one to 32km and the third up to 28km height and they do still work 
http://snowflakeone.ch/index.php?option=com_content&view=article&id=13&Itemid=16&lang=en
there are just a few Pictures on the site the other ones are for comercial purpose
thx
Andy
Nice work!
Watch out though, these guys will be looking down on you:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1236996885
where are you found 35 km of rope? O.o
??? lol
would be a huge weight with 35km of rope
that's why I connected a Mobile to the Arduino so that the sonde can send me an SMS when it has been returned back to the ground...
now you even can hear or see an Airplane
Andy
Perhaps this is the one on TV now too. VERY WELL DONE
Bet not long now for Government come round stop such activity.
¨We cant have that !¨
Didn't get this info. Do you have a link?
The problem is that the balloon and the gas is from the government