How to copy/paste portion of an image

Do you mean bitmap image?

Yes -- an imported jpeg image. I would like to copy a portion of it and paste that portion over an existing portion (esentially "erasing" the original portion that was copied over.)

For most of bitmap editing it should be easier to use gimp or any other bitmap editor.
If you still are sure you want to do it using inkscape, then clipping or masking is what you want. Use development version and select path and your picture at the same time, rightclick → Clipping mask.

hello. I offer next algoritm (if I understood problem clearly):
1) Duplicate image (ctrl-D)
2) Set clipping path around needed area in copied image- use any tool - circle, rectangle, Bezier..
3) Clip the image with the path - choose image & clipping path, then Object ~>Clip ~>Set
4) Move result onto original bitmap in needed place.

Is it help? Cheerz!

Yes. Thanks so much for all your help.

Koptev Oleg wrote:
> Your question #65565 on Inkscape changed:
> https://answers.launchpad.net/inkscape/+question/65565
>
> Koptev Oleg proposed the following answer:
> hello. I offer next algoritm (if I understood problem clearly):
> 1) Duplicate image (ctrl-D)
> 2) Set clipping path around needed area in copied image- use any tool - circle, rectangle, Bezier..
> 3) Clip the image with the path - choose image & clipping path, then Object ~>Clip ~>Set
> 4) Move result onto original bitmap in needed place.
>
> Is it help? Cheerz!
>
>

Thanks mahfiaz, that solved my question.