CSS Rendering List Items in 2 rows

Item 1 | Item 2 | Item 3 | Item 4
| Item 5 | Item 6

This is fine, Item 5 and Item 6 are pushed to the second row because the container has a fixed width.

Now, is it possible to have something similar to above, except that majority of the items will render in the second row? Something like:

Item 1 | Item 2 
| Item 3 | Item 4| Item 5 | Item 6

Basically, I want to render a list of items horizontally, wrapping to the second row as needed, but with majority of the items on the second row if it exists. The number of items to be generated may vary, but will not exceed 2 rows' worth of items.

Not without either manually defining which item starts the new line (with clear:both;), or using javascript to figure out which item should break, and then doing the same as above.