It's happening -- the Wyld Stallyns are back together, and from the looks of things ... more time-traveling hijinks are imminent.

Keanu Reeves and Alex Winter are together again -- 30 years after the release of "Bill & Ted's Excellent Adventure" -- onset Tuesday in New Orleans. The most bodacious duo are filming the long-awaited third installment of the franchise, following the 1991 sequel, "Bill & Ted's Bogus Journey."

In case you aren't familiar ... Bill S. Preston, Esq. (Winter) and Theodore Logan III (Reeves) travel through time via phone booth in the first movie to gather famous historical figures for a class project.

It seems the dudes will be utilizing the phone booth in 'Bill & Ted 3' as well, and some new people from the past -- looks like Gandhi and Sacagawea -- will be joining them.