sneak in. no problem.

You can actually stay in one of the units. I was there in 2003 with a friend and if i remember correctly the 2nd floor is retail space and the 3rd floor has a few units you can reserve for the night. Might be something to look into, probably not very well advertised. Good luck.

I forgot about the rooftop....

If someone there is nice enough to let you in and give you a short tour he/she can take you up to the top, we just happened to be there at the right time... you get a very nice view of the city...

Here is a link that might help - seems to have a link to the hotel in the Unite
mimoa

There is a restaurant at the hotel floor as well with good food and you can easily walk around, even to the roof....

don't know if this has previously been discussed here, but there is also a reproduction of one unit at La Cité de l’Architecture et du Patrimoine in Paris. The effect is a little odd because it is entirely indoors and rather dark (I wished they could have at least done something to reproduce the effect of natural light on the interior) but it is interesting to see the exterior of the unit.

seeing the real thing, given the opportunity, is of course better. but the Cité is definitely not to be missed.

top middle video

- they often sell out so book early.

it might be worth noting that the Marsaille Unité is not the only one available for visiting.

there is also a Unité in Briey-en-Forêt, eastern France, close to Metz and the Luxembourg border. this was the last Unité of Le Corbusier. it was renovated in the late '80's, and is inhabited by local families. the 1st floor (or rather the 1st 'street') La Premiére Rue, is also the name of an association of architects, artists, and other who renovated 32 apartments for use as residences, studios and exhibitions spaces. this are now open to the public for viewing and use for school groups, etc. see:
http://www.lapremiererue.fr/news/la-premiere-rue

also, there is the Unité in Firminy, which was also recently renovated. not sure about visiting it, though they used to use some of the apartments for art exhibitions. in Firminy, there are 4 or 5 other Le Corbusier projects, including the recently completed church, the Saint-Pierre.
http://lecorbusier.ville-firminy.fr/page.php?nIdSousRubrique_PM=20

Thanks for the response,

I ended up booking a night at the Hotel LeCorbusier. It wasn't that expensive (60 Euros) and I figured I might as well stay there considering I'd be rummaging around it anyway. and now I can get to see it at night and day.

I'll let you know how it goes, probably will post some pictures.

Following up the posts by theparsley and dlb, along with the reproduction of the Marseilles unit at the La Cité de l’Architecture et du Patrimoine in Paris, is an exhibit on other Unités. The exhibit mostly deals with the influence of Corbu's Unités, but while I was looking at it, it occurred to me that it would be fun to chase across France on Unité-inspired fieldtrip.

at the one in berlin was pretty easy to snoop around everywhere in 1990. wonder if it still is?

sw, i was able to snoop around the berlin one pretty easily in the summer of 2002...

You can definitely stay there, and its fairly cheap as well, if you have people you are traveling with. Be sure to take one of the small rooms, similar to the dimension he used at La Tourret. It's a very good experience, and you have a wonderful view of the city. You also have access to the roof, but be careful Marseille is supposedly a crime ridden area, but I didn't experience that when I was there. If you want more info, just let me know, but definitely do it.