I recently purchased the Star Wars trilogy on DVD, and I have to say, it's awesome. The changes that George made to this release, as opposed to the 1997 re-release, are perfect all across the board.
In many ways, he's redeemed himself for Willow, the made for television Ewok movies, and making my family poor through merchandising.
Anyway, while reading slashdot a couple days ago, I came across a review detailing the differences between the original release, the 1997 release, and the DVD release.
I was confused, though, as the DVD changes reported in the article were entirely different than what I found on my DVD copy of the trilogy.
So, I'm guessing that there are several versions going around, and I thought I'd just add my own observations to the mix, comparing the DVD updates that I've found to the original theatrical releases...
The Sandcrawler

The original sandcrawler shot was nothing special. Basically, George's special effects team put a toaster on wheels, painted it brown, and made squeaky noises off camera while it rolled by. It was a cool effect at the time, but it never lived up to George's standards.
And why should it? Any two-bit film amateur could redo this shot today without any problem. By simply using a CGI toaster instead of a real one, hours (days?) could be saved, and it would cost almost nothing (toasters are about $30-$80 a pop - the nice ones that toast 4-8 slices of bread at once are kind of expensive - pixels, my friends, are free).

In this updated shot from the new DVD set, we see a much improved scene.
What a lot of people don't realize is that the original scene was hard for children to watch because of all the innocent sand that got run over by the toaster. George, who is well known for his attempts to sanitize the film industry, couldn't stand the sand violence, and replaced the whole scene with a few minutes of Jar-Jar at the beach, playing with a nice inflatable ball. It's rumored that there's an extended version of this scene where Jar-Jar goes to get some cotton candy and ride the ferris wheel on the board-walk, but it's tough nowadays to know who to believe.
There are so many people out there now, just pumping out false information. It's sick.
Anyhoo, I think you'll all agree that the new version kicks major space opera ass.
Han and Greedo in the Cantina

The original release of Star Wars had a scene of terrible violence in it.
As some of you may recall (and as many of us, unfortunately, are unable to forget - even after the therapy), Han Solo, played by Harrison Ford, is at one point cornered by a frog-headed slob in a life-jacket who thinks that Han owes him some money or something.
Han, being a space pirate, whips out his blaster and fries the toad-man in cold blood (it's worth noting that the toad-man might have actually been cold-blooded anyway, so some of the sting of this particular colloquialism is lost, but I'll employ it nonetheless).
I can't tell you how much this screwed me up as a kid. All the nights spent in jail - waking up in the morning with no recollection of what had happened the night before - nothing but a trail of blood, a new line on my police record, and the vague and distant memories of screaming to remind me that whatever had happened the night before, it wasn't pleasant.
Oh, how I wish I could undo the past.
[sigh]
George was irresponsible in his youth, not considering the social ramifications of depicting such immorality on the big screen.
Is there nobody who understands my pain?
The 1997 version wasn't much better. Instead of only Han shooting, the toady thing shoots, too. So, I'm like all, "Great - twice as much violence - when is going to stop, George? When will it all end? And how many people will have to die before you've satisfied your blood-lust?"

Fortunately, George finally saw the light and did the right thing for the DVD version.
What we see here is the totally reworked scene, with no shooting at all! Also, Han, that stupid, mean, violent space pirate, has been replace by Jar-Jar Binks, who is much better suited for the task. What Luke and company needed was a skilled and charming negotiator like Jar-Jar - not some guy who has to whip out his weapons and char the flesh of all those around him every time some bounty hunter comes looking to collect on his hide.
Now, instead of the shooting, there's a conversation between Jar-Jar and Greedo (I think Hugh Grant did the dubbed side of the conversation for Greedo):
Jar-Jar: Me-sa loves-a you-sa, Greedos!
Greedo: Oh, yes? Oh, well, my car is outside if you aren't doing anything.
Then, at the end of the conversation, Jar-Jar farts, which is really funny.
Ha ha.
The Duel

In this scene, if I recall correctly, an unusually tall gnome in a robe is fighting a duel with one of the Environmental Protection Agency's high-risk cleanup crew's inspectors.
They have these "laser-sword" things that are all like, "WHOOOOOM, VOOOOOOM, WHOOO-ROOOM-VOOOOOOM."
Again, the problem here is that all George is teaching us is that your problems with the EPA can be solved by pulling a laser-sword on the inspector when he comes around and trying to chop his head and various appendages off.
There are so many ways to do this that don't involve violence:
- Bribery.
- Not opening the door when the EPA guy knocks.
- Agreeing to the inspection, but then saying that you can't show him all of your house because "It's messy, and the maid hasn't been by yet today."
- Start barking when the inspector knocks - he'll think you're a dog, and that will make him scared.
- Have a trap door out on your porch - open it when the inspector is just over it, and then leave him in the pit below for all of eternity. Can you really blame yourself because somebody else didn't expect to fall into a pit sometime that morning and didn't pack enough food to last several decades, leading to starvation and death? This is a tough call, but it's certainly better than chopping him up with your stupid sword.

Leave it to George to come up with a clever solution.
In the new DVD scene, we can see that George replaced the EPA guy with - yup! - Jar-Jar Binks.
And instead of resorting to violence to get the gnome to comply with the inspection, Jar-Jar simply wraps his tongue around the gnome's laser-sword, thus immobilizing him mid-swing, and making it possible to continue the inspection without shedding a drop of blood.
Also, Jar-Jar farts at the end of this scene, too, because that kind of humor never gets old. It's especially funny here because of the suit. You're like all, "Where did the fart go?"
If that doesn't make for exciting movie fodder, then I don't know what does.
I guess that's just par for the course, though, for a genius like George who had the incredible insight to realize that what people really want out of life in these modern times is a two-hour film consisting of computer-generated muppets trying to balance the Galactic Trade Federation's checkbook.
George - we salute you.