I wish I could rate the two halves of the movie separately. The first half was kinda bad--and I almost just kind of shrugged and turned it off, but the second half definitely more than makes up for it.
In the first half of the movie, Priety Zinga and Abishek Bachchan meet in a train station, where both are waiting for their "fiances." They both embark on somewhat rambly, pointless,unbelievable tales of how they met their sweethearts (filled with some really bad song and dance routines).
I don't want to give away the rest of the plot, but let's just say the second half is better. The highlight of the second half is a dance off, filled with some pretty awesome dancing, and it's just plain fun. I almost dare you to watch it and not grin, it's just silly and fun.
As a side note, it's almost worth it to watch this movie just for the sake of seeing Amitabh Bachchan dressed as a half punk rocker, half hippie. http://bollywood.celebden.com/wp-content/uploads/2007/05/5-sml.jpg By the way. And fyi, he doesn't have a character or anything like that, he just dances at random interludes...it's strange (except at the very end, I think they were trying to go for something important, but I missed it, ahh well).
Finally, on a total side note from the movie, it honestly saddened me to see how much weight Preity Zinta had lost. I'm used to her in Veer-Zaara-where she looks like a gorgeous, healthy person. Here, she was just tiny.
I have to say I hate how westernized bollywood is getting. I mean, some of it's all in good fun, but the girls are shrinking in size. Up until a few years ago, I think girls could watch bollywood, and see gorgeous, healthy women (ones that it would be OK to aspire to look like), but now bollywood actresses are getting more and more "westernized" (ie overly skinny). And that's too bad.
Well, anyway--JBJ is worth a couple hours, but you've got to make it through a rather boring first half before it gets fun!