Last night around midnight Marelle and I noticed a
long rack of brand new bikes lit up with lit green
lights. Our hosts explained this is a new thing this
month in the city. Every neighborhood has a big rack
of these new bikes. You just insert your visa card and
the bike unlocks 24/7. You can then ride anywhere in
Paris for 30 minutes for free! If you need more than
30 minutes and do not want to pay four euros an hour
additionally, you simply check in the bike you have
and check out another and you are good for another 30
minutes. Theoretically you can do this all day and
ride for free! The whole thing is computer monitored
and if too many bikes are left at one place a truck
comes by and redistributes them around the city. The
bikes are all equipped with night-lights and baskets
for shopping!

Link... [1]