4 columns to 2 columns with Twitter Bootstrap

Answer 1

You'll just need to override the CSS for the spans in the @media query corresponding to tablets.

So you can try something like this:

// Tablets & small desktops only
@media (min-width: 768px) and (max-width: 979px) {
  [class*=span] {
    width: 50%;
  }
}

Of course, adjustments may need to be made. Because of padding and margins, the width may not actually be 50%.