Yes, the giant balloon in the Welcome Area is fying high. The 15 minute tour is designed to show trial users some nearby attractions: Nexus Prime, LindenWorld, Shangri-La, and DarkWood/DarkLife.
The tours are hosted by a special group of residents with the title Sky Guide. If you want a ride and don’t see a Sky Guide nearby, ask a Liaison to check if one is online.
If you are interested in being a Sky Guide and have been in SL for at least a month, then IM Char Linden in world. Sky Guides receive a small honorarium for their time.