Paris - Any info on Tour de France and Jazz Festival?

Hi all,

I'm going to Paris this weekend. We've done the obvious 'sights' before and so are looking for something a bit different to do.

I know the Tour de France finishes on the Champs Elysee on Sunday and would like to go see it. I'm sure it will be really busy, so can anyone please recommend a good spot to head for from which we'll be able to see some of it?

Also, I heard there was a jazz festival on in Paris at the moment in one of the parks. What's it like? Do you need to get tickets in advance?

Any info on these two, and anything else you can recommend that is happening this weekend during the day or night would be much appreciated

Thanks
Alice