A 'poor persons' HDR can be done with ONE good photo. Load it into a decent photo editor, and adjust the exposure down two stops and save it, then repeat again but up 2 stops. Now with the 3 copies, run it through a HDR generator. Not as good as bracketing directly in the camera, but can yield acceptable results.
No. This will give the visual effect of HDR (which many think is something to be avoided - HDR should be a tool, not a style), but does not increase the actual dynamic range.
Really, if you are going down that road I prefer manually blending the different exposures in Photoshop. 5 years ago, that is how I dealt with bracketed exposures as well. Back then HDR still had a very definite look which I really tried to avoid.
Even if you don't have/can't use a tripod , software stabilization is pretty good for handheld use. And there are a few ways you can pull that with OpenCV, so it's not that expensive editing software is involved (of course, Photoshop has it, and in a "photographer friendly way").
I've combined hand held bracketed shots. There are problems at the edges of things due to slight shifts in location and parallax but this can be handled in photoshop and HDR (I used to use Photomatix) does a good job at removing ghosting and edge artifacts.
