Do you know if there are alot of places in Paris that have free WiFi?
Free WiFi is available in libraries and parks. Here's a link to a page with descriptions and maps.
http://www.paris.fr/portail/economie/portal.lut?page_id=7799
McDonald's and Starbucks will give you 30 minutes of free wifi with purchase, reasonable rates after that.
Scroll down under the "classic view" about three paras, and you find this question has been asked twice in the last day, and several answers given.