The California Near Space Project is at it again. Last year, they became the first team to achieve a transatlantic crossing using a latex weather balloon, and they launched from California. Above is last year's flight path.
They have another long-duration flight over the great lakes right now, and you can follow the action here: http://aprs.fi/k6rpt-12. Note that they're having some GPS trouble, so the position reports can be a little bit weird, but generally the position updates every 2 minutes. More information on the team can be found on their website at http://www.californianearspaceproject.com.
Comments
Quick update... the balloon was just picked up via APRS just off the coast of Morocco... it's still alive, making this (possibly) the second trans-atlantic flight by the California Near Space Project. The tracking link above is still good, if you're interested. Congrats to the CNSP team!
nifty!