columnize.js

var columnize = function ( count , colClass ) {
    colClass = colClass || 'span'+(12/count)
    var columns = [],div
    
    // builds the columns
    while (count--) {
        div = document.createElement('div')
        div.setAttribute('class', colClass )
        columns.push(div)
    }
    
    return function (elements ){
        return columnize.parseElements(elements, columns)
    }
}
columnize.parseElements = function ( elements , columns) {
    var  cols = columns.concat()
        ,frag = document.createDocumentFragment()
        ,col,div, i = 0, len = elements.length
    
    // puts the elements into the columns
    while(len--) {
        if(!col || col == columns.length) col = 0
        cols[col++].appendChild(elements[i++].cloneNode(true))
    }
    
    // puts the columns into a fragment
    cols.forEach(function (el) {
        frag.appendChild(el)
    })
    
    return frag
}

columnize.two = columnize(2)            
columnize.three = columnize(3)
columnize.four = columnize(4)

usage.js

var pees = document.getElementsByTagName('p');
var row = document.getElementById('row');
var threeColumns = columnize(3);

row.appendChild(threeColumns(pees))