[OS X TeX] pagebreak within a paragraph in a twocolumn setup

[Reich Ingo]

Hi everybody,
I'd like to set text in two essentially independent columns:

_________    _______________________
|                   |     
|                                                    |
|                   |     
|                                                    |
|                   |     
|                                                    |
|                   |     
|                                                    |
|                   |     
|                                                    |
|                   |    |  text text  text  text  text  text   |
----------------------------------------------------------------   
pagebreak
|                   |    |  text  text  text  text  text  text  |
|                   |     
|                                                    |
|                   |     
|                                                    |


This probably could be done easily in some kind of tabular or two  
minipage environments.  But there are two complications:

1. Suppose there is a long paragraph in one of the columns which is  
too long to fit on the page. Then, what I'd like to have, is an  
automatic pagebreak *within* the paragraph, i.e. (i) fill the page  
with the first part of the paragraph, then continue on the next page  
with the rest of the paragraph in twocolumn mode.

2. I'd like to have different background colors for the two colums  
(also extending across the page).

I know that supertabular or xtab allows for pagebreaks within  
tabulars, but only between two rows. What I rather need is a break  
within a cell.

So, does anybody know some way to have an automatic pagebreak within a  
tabular cell or whithin a minipage environment? Or is there some  
alternative? (I tried the context paragraph setting, which is nice,  
but also puts the whole paragraph on the next page. Anyway, I'd rather  
stick to standard latex.)

Any ideas?
Best, Ingo