<template name="postsList">
<div class="posts">
   <div class='row-fluid' style="margin-left:1%">
      {{breakInit}}
      {{#each posts}}
         <div class="span3">
           {{> postItem}}
         </div>
         {{breakNow}}
      {{/each}}
   </div>
</div>
</template>

Template.postsList.breakInit = function() {
Template.postsList.docCount = 0 ;
};

Template.postsList.breakNow = function() {
count=Template.postsList.docCount + 1 ;
result="";
if ( count == 4 ) {
    count = 0 ;
    Template.postsList.docCount = count ;
    result="</div><div class=row>" ;
};
Template.postsList.docCount = count ;
return new Handlebars.SafeString(result);
};

<div id="main" class="row-fluid">
  <div class="posts">
    <div class="row">
      <div class="span3"> … </div>
      <div class="span3"> … </div>
      <div class="span3"> … </div>
      <div class="span3"> … </div>
      <div class="row"> … </div>  <-- The problem...
      <div class="span3"> … </div>
      <div class="span3"> … </div>
    </div>
  </div>
</div>

Template.projectList.helpers({
    projects: function () {
        all = Projects.find({}).fetch();
        chunks = [];
        size = 4
        while (all.length > size) {
            chunks.push({ row: all.slice(0, size)});
            all = all.slice(size);
        }
        chunks.push({row: all});
        return chunks;
    }
});

<template name="projectList">
  {{#each projects}}
    {{> projectRow }}
  {{/each}}
</template>

<template name='projectRow'>
  <div class='row span12'>
    {{#each row }}
      {{> projectItem}}
    {{/each}}
  </div>
</template>

<template name="projectItem">
  <div class="span4">
    <h3><a href="{{projectPagePath this}}"> {{title}} </a></h3>
    <p> {{subtitle}} </p>
    <p> {{description}} </p>
    <p><img src="{{image}}"/></p>
    <p> {{openPositions}} </p>
  </div>
</template>

{{#each rows}}
    <div class="row-fluid">
        {{#each posts row}}
            <div class="span3">
                {{> postItem}}
            </div>
        {{/each}}
    </div>
{{/each}}

Template.postsList.rows = function () {
    // 1. Get cursor of posts (cursor = posts.find({...});
    // 2. Get count from cursor (count = cursor.count());
    // 3. Divide count by desired columns per row, then Math.ceil it (I think!)
    // 4. Return an array of objects each containing a "row" key, with some various values (current row probably, count, etc)
};

Template.postsList.posts = function (row) {
    // Return a cursor of posts that is offset and limited (see meteor docs) based on values found in the row object
};