I get why quad-band before you go is ideal, but I would imagine that buying a *really* cheap 900/1800 phone on the street in Paris should be an okay option too. I got one in a street market in London for 10 pounds - a simple Nokia, new in the box. Seems like something similar should be easy to get in Paris.

Granted, it's a *very* simple phone - talk & text, no smartphone or data capabilities. No way to tether it, no apps, no nothing. Literally a 90's-style little brick.

I then bought SIMs for it all over Europe and North Africa...whatever provider had a decent Europe-to-U.S. rate.

Much less elegant than owning a true worldphone...but cheap and sufficient for a traveler who doesn't need to take inbound calls.