I think someone here missed the latest news release mentioning UNTETHERED tests of a LTA platform:
FORT LAUDERDALE, Fla. and STUTTGART, Germany, Feb. 14, 2008 (PRIME NEWSWIRE) -- Sanswire Networks, subsidiary of GlobeTel Communications Corp. (Pink Sheets:GTEM), and TAO-Technologies GmbH today announced that they've begun testing a lighter-than-air (LTA) platform capable of operating at altitudes of approximately 65,000 ft. The program's ultimate goal is to produce long endurance, LTA vehicles that provide various security- and communications-related services from the stratosphere for extended time periods.
The current phase of the program consists of several untethered air- and ground-based tests of the proprietary components and systems.