I have a website with a two column layout, like there are dozens I guess. I am currently converting the website to having a responsive layout, and what I see most often is that the sidebar is just suppressed and only the main content is shown.
That looks good, but I would like to have some way to keep the sidebar reachable. I can think of a few alternatives:
What is your approach to handle something like this?
This article by Luke Wroblewski outlines some of the most common responsive layout patterns: http://www.lukew.com/ff/entry.asp?1514
The layout you're describing where the sidebar slides down below the primary content is certainly the most common approach. I hear what you're saying that it's not obvious that it's down there, but in my experience, users will scroll.
If you're concerned, Luke's article lists ways to reveal navigation and some alternate approaches as well. In particular you may be interested in the "off canvas" pattern he describes, which most people are familiar with from the Facebook app, where you click the nav link and it slides in from offscreen.