Two stores in one?

Hi
I wonder if its possible to have two zen cart stores in one?
Is there a modification so I can use the same admin and db whit out having two different installations of zen cart?

I need help. This is getting me crazy.

I have two stores:
Public page nr1: http://www.brollopsnatten.se/
Actual page nr1: http://brollopsnatten.se.scorpionshops.com/
Public page nr2: http://www.bikinimode.se/
Actual page nr2: http://brollopsnatten.se.scorpionshops.com/bikinimode.se/www/

The two stores shearing the same db.
The problem I have is that I want them to be almost the same but whit different looks and so on.
And I achieved that nicely if I use the actual pages.
The problem comes on the public page use.
Then the costumers cant see the products they added on one store in the other one.
As I see it, it has to be a cookie/session problem????
Is there some one how can help me to think something out, so I can get the two stores working together as they do on the actual page addresses but whit the public page addresses?

Is there a way to store sessions in URL instead of cookie?

Is there a way to store sessions in URL instead of cookie?

Is there a way to store sessions in URL instead of cookie?

Look for the multi-store mod in the downloads section.

Yes but that's one what I am looking for.
I need two installations on two separate www split a shopping cart