How do you use Twitter Bootstrap to create a table-like list structure, where some columns take as much space, as required to accommodate the widest element of that column,
As others said, you should use regular tables where they make sense. Also, CSS3 display:table can be a good solution.
Depending on the use case, there is a different solution you could consider:
https://github.com/donquixote/bootstrap-autocolumns/blob/master/bootstrap-autocolumns.css
This is a piece of CSS that adds "col-sm-auto" in addition to "col-sm-1", "col-sm-5" etc.
(Atm, I would recommend to just copy this to a custom css file and adjust to your needs.)
Left
Right
Middle
Here is a fiddle: http://jsfiddle.net/9wzqz/
The left/right columns will expand to full width, if you fill them with long text. Better use them for fixed-width stuff like images.
The middle column will only take the full available width if it has enough content in it.