A special edition, Human Traffic Remixed, is available on DVD. This is re-cut with new scenes, new CGI effects, and new tracks.
The US version was edited to remove certain cultural references that it was felt Stateside audiences would be unable to identify with. Notable amongst the changes was the removal of the "Summer of Love", late 80s/early 90s flashback sequence - complete with dummies, glowsticks, et al. Apparently this - and other refences - were thought to have been confusing for American youths whose similar "old school rave" period came rather more recently.
US version - when kip is introducing Lulu - he says that he has "recently become clubbing partners" where the UK version he says "recently become dropping partners".