Montpellier is a city in the South of France.
Apart from an attractive city in itself, it is situated next to a main motorway A9/E15 connecting cities such as Perpignan and Barcelona to the South, Aix-en-Provence and Marseille to the East, Lyon and Paris to the North, and Toulouse and Bordeaux to the West.
The tramway line in Montpellier, line 2 (the flower tram), goes directly to a péage (toll plaza). Take tram line 2 from the train station, in the direction of "St. Jean de Vedas", then get out at the next-to-last stop, "St. Jean le Sec". At the stop look around and you will see a péage behind a roundabout.
EDIT 2017: The "péage" doesn't exist anymore. Hitchhiking is still possible in the roundabout, between the tramway stop and the highway entrance, with a sign.
The easy spot
The roundabout is a good spot for both directions. Good traffic at normal hours. In case you're going south, "Béziers" is a good city to put on your sign. The next petrol station is right out of Montpellier, and there is another one before Béziers.
If you're going north, you can write "Nimes" on your sign. There is a petrol station before (Ambrussum).
The hard-core spot
If the above spot is too low on traffic (or too easy) for your taste, you can continue walking past the small péage to the multi-lane one where all the cars from North or South have to stop. To reach it, you must walk for 10 minutes beyond the first péage. It is illegal and quite dangerous to walk on the autoroute, so you need to walk far to the side, staying on the grass if possible. You will see the big péage from where you can find a 300 or 400 km ride in any direction.
Attention: there is no parking spot after the péage so you'll have to do it at the very place the people pay. Which is sometimes tolerated by the personnel, and sometimes not.
EDIT 2017: The first "péage" doesn't exist anymore. About the big one, it depends on the direction you're going. Going East/North won't work, as people arriving to this toll stop in or around Montpellier. (The main traffic that's going further takes a different route, quicker, right in the middle of the two big tolls with no possibility to stop.) Going West/South is still possible from this spot (traffic from Montpellier and surroundings).
This link shows all the péages, exits and petrol stations of the A9.
The "all directions" tip above, or: If you like safe and easy hitchhiking, it's advised to take Tram number 1 to Odysseum, get off at Place de France, which is one stop before the last stop, then walk a bit back to the roundabout and go the Av. du Mondial up to the north. Walk straight and you will see a hill on the left, right in front of the highway. Go up (better to have good shoes on!) and you find at the top this brilliant hitchhiking spot - Elf petrol station. You can try there, or stand with a sign on Av Pierre Mendes, just before the entrance to the station. where it is?
The "all directions" tip, above, by far seems the best bet as these two mean hitching out of a roundabout, which is never as favorable as a péage. But if in any case you need to hitch out without using the tram or péage others have used these routes:
Option One: Another option is to get to Place de L'Europe (), for example by taking tramline 1. From there you can already see signs to the motorway. You can either follow those signs and the main road Avenue de Président Pierre Mendes France for about 15 to 20 minutes, or get a ride from where this road starts to either your destination or to a better location further up the road, at the roundabout where the main motorway A9/E15 actually connects to the Avenue de Président Pierre Mendes France.
Note: There is not a very good spot for cars to stop, but they stop at the roundabout for traffic with enough time to ask drivers for a ride, and for them to open the door.
Option Two: A second option is the roundabout off Avenue de Palavas (near Tramway 4 - Garcia Lorca). However there is no good spot for cars to stop at the roundabout, and nowhere on the ramp either. Zac waited for an entire day for a ride to Perpignan without luck and shamefully retreated to the train station.
Option Three: Take tram to stop "Sabines" and walk down Avenue d'El Alamein. You'll find roundabout.
It seems the tram is not checked often by ticket controllers. Only sometimes at the main train station and the controllers are many in white shirts, easy to see.
You can find free luggage storage at the "Musée Fabre," a big new museum in the center of Montpellier, close to "Place de la Comedie". Of course the luggage storage is for people who visit the museum, but if there is a lot of people they won't pay attention. It's a room on the left in the entrance, there are boxes where you can put a bag. You need to put one coin inside to have the key which they give you back.
Update 07/2015 only for small luggage and a guad is watching
It's a nice painting museum for people who like art. Use an ISIC card (or say you have one) for free entrance.
You can get free veggies and fruits at the end of the market on Figuerolles. They close by 11/12.
June 2017: Every Thursday, at least during the summer, in the big gazebo in the parc Esplanade, there is a huge unofficial (ie. spontaneous, traditional, certainly doesn't cost money) party with musicians and traditional French dancing. It's lots of fun, go make some friends.
There is a flea market on Sunday (early) around the tram stop Mosson, end of line 1 Lots of random crap, lots of clothes, some food. Apparently there will be lots of stuff left over by vendors around 1-1:30. There are a few other flea markets in town.
The organization Mama Sound publishes a small pamphlet (free) every month that lists all the events happening in town.