I have a little mind puzzle here. This idea was bugging me since I saw a question about breaking cells in a table on a page break. Let's think of a table row that's built from cells that are paragraphs and we want to have normal page breaks, as if we had just one paragraph to deal with. It doesn't have to be one of the regular table environments. Just have for example paragraphs of
.45\linewidth with space between them.
Suppose we have two paragraphs running side-by-side and let's assume that nothing fancy happens in them - just plain text, same font and size and identical baseline skips. Theoretically it should be possible to save those paragraphs in boxes of given widths where they will be converted into lines, then match each line from one cell with the corresponding line from the other and add those (boxed or haligned) pairs to the vertical list, letting TeX do the usual page breaking.
Can this be achieved fairly easily?