Batman’s blockbusting return has broken yet another record over the weekend. The Dark Knight passed the $500 million mark (that’s US domestic, we’re talking over $919 million worldwide) on Sunday, just 45 days after being released. To put that in perspective, the biggest film of all time, Titanic, took 91 days to hit that point. Impressive huh?But while it’s a new record, it still looks like the superhero phenomenon won’t hit the most-successful-film-of-all-time number one slot presently occupied by James Cameron’s watery epic, which grossed $600 million in the States back in 1997/98. Current estimates are that The Dark Knight will finish around $60 million short of that target while, despite being about to become one of only four movies to crest the billion dollar mark globally, it won’t even come close to beating Titanic‘s $1.8 worldwide haul.

The Dark Knight has displayed impressive legs, though, and this weekend – which is the Labor Day weekend in the States – it posted a three-day gross of around $8.75 million to take third place.

At a very slow time for the US box office, that was enough to put it behind Babylon A.D., the Vin Diesel vehicle that has been spectacularly disowned by its director, Matthieu Kassovitz, which took second place with a three-day total of $9.7 million.

Taking the top spot, though, for the third week running was Ben Stiller’s Tropic Thunder, with a three-day take of $11.5 million. For all its consistency, though, the R-rated comedy will do well to clear $100 million.

There were two other new releases of some note this weekend. Traitor, a low-key but decent thriller starring Don Cheadle and Guy Pearce, which was co-written by Steve Martin (yes, that Steve Martin), posted a $7.9 million opening, which will be some comfort to Overture Films, the fledgling studio behind the film.

And, just to prove that there is a God, the inept Disaster Movie, the latest in the series of laugh-free spoofs from the writing/directing team of Jason Friedberg and Aaron Seltzer (who inflicted Epic Movie and Meet The Spartans upon an unsuspecting world like the cinematic equivalent of a SARS outbreak), stiffed on its opening, with a poor take of just $6.1 million.

There’s talk, though, that Sci-Fi Movie has already been given the greenlight, although we’re hoping that Lionsgate, once they see the critical reception and box office for Disaster Movie, they’ll have a hasty rethink