I have been searching long time for a Tour Guide Script with sim crossing abilities. Although Outworldz.com has some neat tour guides on offer at https://www.outworldz.com/cgi/freescripts.plx?Category=Tour%20Guide, establishing one that could cross regions wasn't an option.  Until I stumbled upon Shinobar Martinek's regions and played with the Hawk Tour that brought me across several sims rather seamlesly.  I was thrilled and decided to try out her car tour, submarine tour too at her HG address: http://jogrid.net:8002:Shinobar Annex.

To learn more about the easy to configure tour guide script, visit http://shino.pos.to/secondlife/blog/?viewDetailed=00005 and use google translate

The tour guide works like a charm (on VAR regions and regular sims alike) and, for once, no scripting experience required ^^: just edit the notecard and enter your coordinates and you are done.
Spoiler alert: OpenSim 0.9.or higher is required.