I was down at Friedrichshafen for Aero 2003 and having a quiet beer on the promenade when a gentle buzzing noise overhead materialised as a Zeppelin NT. Quite spooky but I gather they do pleasure flights over the Bodensee for paying guests. There is also the Zeppelin Museum in the town which is very interesting. Ryanair go there direct from Stansted so it's all very easy. The Zeppelin works is on the airfield and they seem to be set up for visitors. Hope this helps.