White Star plans to launch a transatlantic balloon flight attempt at 0000 UTC (Thursday evening for most of the US). If you’re a ham operator set up for digital modes, you can monitor the telemetry transmissions on the 40m band and automatically report them. The flights predictions call for a three day flight.
During the flight, you’re likely to find other people who are following the action in the #highaltitude chat on freenode IRC.
Also if you’re a ham using Ubuntu, check out the Ubuntu-hams team, or drop into the #ubuntu-hams chat on freenode IRC.
It can be a lot of fun to help track the balloon flights. Here’s a previous post I made about a tracking adventure.