Reference other groups/foreign keys/fields

Hi, and first off: big thanks for providing your free plugin, the clean interface and the ton of documentation!

However, I couldn’t find anything on your website or in the forum so here it goes: is it possible to reference a field to another field from a different group? (Example below)

I’m aiming at building a website to handle different kind of data, basically people submit data to a form, the data is stored in the db, they can change it and after some time generate some nice charts.

Example: I’m setting up a new group to store “states” (with a “title”-field like California, Texas, …).
Now, I’m creating a new group to store “organisations” and every organisation should have a field “state”. The possible values for this field should come from the group “states” and its “title” (or ID) field. So I’m looking for a drpodown-fieldtype, that gets its values from a different field.
To go further: I also have particpants/users and need every organisation to have a user (1:n relationship), is that possible with your plugin? Do I maybe need an addon?

So basically I’m for a plugin which allows me to create forms, cross-reference them, store the data and add some logical “programming code” to all that.

Thanks in advance!