In answer to the person who made the comment about how the film drags on and who believed there was no purpose to the role of Jess's brother here is my response:
The role of Jess's brother is to provide a form of dramatic irony in the story. Craig Sheffer/Norman could have foreseen the troubles associated with living life to the full by looking at how Jess's brother turned out. There are various instances where Brad Pitt and his lives run in parallel, for example, when Jess's brother takes Craig Sheffer to a disjointed bar and subsequently he finds Brad Pitt there a few days later. The dramatic irony was there so Craig Sheffer's character would have a bigger emotional turmoil at his brothers death, knowing he could have done more to prevent it and subsequently creates a more compelling mood in the film.

I get to the cinema every week or so, and regularly check out this site, but never before have I felt compelled to comment on a film.
To my all time list of shockingly bad films - Last Man Standing, Spawn, The Bone Collector - I can now add the drivel that was 'Hollow Man'.
From the awful opening titles - a ridiculously over-long run through of cast and crew put together with alphabetti spaghetti - through to the insulting finale - a world record number of cliches and some of the most absurd dialogue and acting to have ever made it to cinema - this film is dismal, and only the impressive computer graphics keep you from walking out long before the end.
This isn't just my opinion - it was that of my friends, and everyone around us. When large sections of an audience are laughing and groaning during and after a serious thriller, its clear that the film is hopeless.
Not only that, it was sick too. The director took the action beyond the bounds of realistic fare for a violent film, and into the realms of an over the top blood soaked B-movie. It's difficult not to imagine the director as some sort of dirty old man, because the extent of the invisible man's forays out of the lab and into the outside world extended only to two attempts at having a feel of some breasts. Perhaps sex could well be the first thing on a bloke's mind if made invisible, but aside from the aesthetic pleasures of the ladies involved, it hardly makes entertaining cinema.
[spoilers follow]
Get past the films sick exterior, and things are even worse. Whilst Kevin Bacon does a good job of acting increasingly twisted as 'hollow man', the rest of them - perhaps handicapped by a dire script - do an even better job of being hollow cast. One long time member of the team is found strangled in a locker by the invisible man, "He's finally snapped" shrugs one colleague without a hint of emotion. This is par for the course, and the lab team swing between sheer terror and complete indifference with such speed that you wonder how they got into acting. They pad their way through the lab corridors terrified, guns poised, but then seconds later one of the crew skips happily off back down the corridor to get blood for a hurt colleague. The lead female treats the invisible man with courtesy and good humour even after he's insulted and abused her, and there seems to be little reaction to his breakouts, even after he drowns the Pentagon chief, "He drowned in his pool last night" reports the same female, spectacularly failing to put two and two together.
The script is littered with this kind of badly acted pedestrian dialogue, and the rest is just an A-Z of film cliches, which get laid on thicker and faster as the film progresses to the point of complete disbelief and amusement at the end.
The 'eureka' moment at the computer, the female undressing at the window, the looped security video - the list really is endless - the predictable disregard for strength in numbers, the decision not to kill the two main stars but just put them in a place of probable impending death and leave them to their own devices, the almost-dead good guy appearing out of nothing to save the woman, the bomb and ubiquitous countdown timer, the fireball explosion which just burns up before reaching the heroes, the falling lift which just stops before hitting them, and more than anything else, the immortality of the bad guy.
The invisible man is burnt to a shred with a makeshift flame-thrower, electrocuted, whacked round the head with a bar which had just sliced straight through one of the lesser actors, and then having apparently survived the explosion, fireball and total destruction of the labs, has more than enough life left to climb up through the fireball for one last pop at the films heroes - by which stage the disbelieving audience are cringing and looking at their watches.
That this exceptionally bad film actually made it to the cinema is astounding. Even the name of the film is as hopeless as the movie itself, and not even impressive special effects come anywhere near saving this one, which should be avoided at all costs.