The extended version: Some differences I noticed...
I know that I'm usually curious about the difference between the normal and unrated/extended/whatever versions, so I thought I'd post a list of the differences that I noticed.
When Adrian comes into Kumar's apartment, the toilet flushes and there's a scene where Adrian confesses that he's been renting out Kumar's bathroom to homeless people. This ties in with Kumar's line that the apartment smells like s***. In the extended version, they both walk to the couch, in the normal version, Kumar never gets up. The second guy's shopping cart can be seen in the entryway in the normal version as well as the door being open.
Harold and Todd stop at White Castle on the way home for some "comfort food" and discuss the preparations for Maria's family.
There are a couple more lines of dialog between Harold and Carlos about the "faux" tree.
The Korean gang in the flashback story includes a female member and the stabbing is actually shown.
After Kumar gets out of the SUV at Harold's house, Adrian comments out loud about the size of the house, number of bathrooms and the amount of money he could make.
The song "It's a Very Jolly Day to Die" is missing from the claymation scene, it only has the music and regular dialog. The snowman taunts them with bad puns in a Scottish accent. There's a lot more death and destruction, including a lot more vehicles crashing in the street scene. The cutaway back to reality showing them pinching the boys cheeks is missing. There's a dissolve back to reality and Harold gets hit with a snowball, rather than the claymation part just ending.
There are a few extra jokes in the diner scene.
The director's rant after the rehearsal is a little longer and has some different dialog.
The heaven club scene is a little longer and the order of some shots has changed. The bartenders recognize NPH, Jesus spots him from the couch and tells the girls that he'll introduce them. NPH comes onto the girls before Jesus introduces himself. There are a few extra lines and the scene ends the same. The "dirty hippy" line is missing though.
Adrian is shown at Harold's party, accepting money from a homeless guy, implying that he's renting out Harold's bathroom.