Things to do in Paris  

Clignancourt Flea Market
on both Saturday & Sunday morning, I think Saturday starts earlier.
http://www.parisperfect.com/paris-flea-markets.php

One of my favorite
foraging sites, the Porte de Vanves Flea Market, on Saturday and Sunday mornings. Saturdays are bigger (more dealers) than Sundays.
30 yards from the Porte de Vanves metro stop, just inside the Peripherique.
http://www.discoverfrance.net/France/Paris/Shopping/Paris_fleamkts2.shtml

Thanks Riki and Robert
They look amazing, but unfortunately we are only going to be there in the week not a weekend....oh well, thanks.

Arts Decoratis
You should visit the Musée des Arts Decoratifs.
They have a great furniture collection from Louis XIV till now.
And somethime a good temporary exhibition.
They also have a good museum shop.
It is near the Louvre.
If you are there: visit the nearby Palais Royal; small but beautiful inner courtyard with small boutiques (vintage couture, extraordinary perfume shop (almost a museum by itself) of Serge Lutens, ...). One of my favorite places in Paris!
http://www.lesartsdecoratifs.fr/english-439/exhibitions/current-events

Hi. I was in Paris last...
Hi. I was in Paris last summer. You have to go to le Centre George Pompidou in le Marais. The art collection is incredible. This museum was my "coup de coeur". Saint-Germain-des-Prés is also an arrondissement you want to visit. Just take the time to enjoy walking in the streets to enjoy the life! Paris was wonderful! Benoît

Nice
place to eat- not the greatest food in the world- but just perfectly Parisian
http://www.restaurant-chartier.com/www/visit/filsdesans.php

I really like "Le petit...
I really like "Le petit Cler" on Cler (7e arr., near Eiffel Tower). The "menu du jour" was good. The neighbourhood was also beautiful (I really enjoyed rue Grenelle). For lunch, I prefered to get a baguette in a boulangerie. You can get a good lunch (baguette, beverage and patisserie) for 5 - 6 euros! Then, you find a nice park, and you enjoy the lunch hour!

merci beaucoup!
brilliant, thanks everyone, very excited by all of those suggestions!

when you go to the cimetary...
when you go to the cimetary of Père La Chaise, and need something small (or big) to eat, look for a little restaurant called La Mère La Chaise.
It feels authentic, the interior is nicely done and the food is great. I ate one of their cassolettes and was pleasantly suprised.
adress: 78, Boulevard de Ménilmontant, 75020 Paris
enjoy yourselfs!

Walk along the Seine...
Then mate.
Go to Pompidou Centre and be thankful that Piano got deep into engineering after that...
Then mate.
Visit Renzo Piano Building Workshop
36 Rue Archives, 75004 Paris, France
01 44 61 49 00‎...
Then mate.
Take in I.M. Pei's disfigurement of the Louvre...
Go some where far from it and mate some more.
Visit the Eiffel Tower...
Mate somewhere in sight of it.
Visit Renzo Piano's IRCAM Extention...
Mate some more.
Visit Corbu's Maisons Jaoul and be grateful the fascists were defeated...
Mate with exhuberance.
Visit La Grande Arche, by Johann Otto von Spreckelsen, then visit Arch d'Triomphe, then contemplate which arch you prefer and why?
Then mate.
Then stop visiting anything.
Just keep mating.
Paris is for lovers.

Strikes
Hi. Make sure that the Museums are open... some are on strike... Benoît
http://www.radio-canada.ca/nouvelles/arts_et_spectacles/2009/12/02/001-m...

Great restaurant!
La Rotisserie du Beaujolais is a wonderful, more homestyle sister restaurant of la Tour D'Argent. Much less expensive as well. A zagat link is below. Have a wonderful trip!
http://www.zagat.com/Verticals/PropertyDetails.aspx?VID=8&R=69605