My pattern normally looks something like using negative margins to achieve "virtual columns" rather than tightly coupling the mark-up to a specific presentation. I guess that has something to do with it. I tend to use negative margins rather than the simple float left and right technique. I feel using negative margins is much more flexible and doesn't make it necessary to wrap multiple elements to position them to the left, right, etc. With negative margins that can all be handles virtually without any type of "presentational" wrapper such as column or sidebar. Though I do use sidebar at times, I don't think that is nearly as bad as column. I think of sidebar more like aside, as you just said.
<div id ="masthead">
<p>My Site Logo/App/Name</p>
<!-- main nav and whatever other crap.. -->
<div>user generated body content blah blah blah...</div>
<!-- repeat links, copyright, site info, etc -->
<!-- throw this below container when dealing with a sticky footer -->
That was what I was referring to when I said it can require additional CSS. In most cases the content in the sidebar will change based on page, user, etc. So it requires a little foresight in regards to organizing the CSS rules best based on those dynamic changes in supporting content.
That said, how about rails? I have seen that used in places. Where something will be named rail instead of column. I think that is a little more "semantically" correct than column actually based on the definition of rail.
a steel bar or continuous line of bars laid on the ground as one of a pair forming a railroad track.
Column is based on vertical alignment where as rail is an association of items, not based on positioning.
Very true, but there are definite patterns in place that we reuse everywhere changing/rethinking time to time that aid in production of all associated assets and quality of a website/app, not to mention consistency. Its those patterns that I and I'm sure everyone time to time as mentioned enjoy looking at and thinking, how I can do this better, or maybe I'm thinking to into it.
One of those patterns that I got else where yet can't remember is handling "presentational headings". You know, those headings that are just there for mainly presentational purposes like Menu (even though the content is obviously a menu) or headings which aren't really important to the document structure such as; Recent Articles in the above example. In those cases I generally turn to the definition list instead of using headings, because in most cases in regards to aside content those "headings" aren't really that significant to the document structure and its always difficult to determine the "proper" consistent heading that should be used across a complex, dynamically driven site for aside/sidebar content such as; featured item, recent items, cart, etc, any widget/block that is continuous on almost all pages yet yes little significant to the main content on the page.