I have no idea what to call this, so am having a hard time finding the information on wordpress.org. I am sure there is a way to post a blog from another web site, copying part of the site and the link to it, and then commenting on it. I believe such a tool would also allow you to notify the owner of the original site that you are doing so, and where your article is.

I'd ask on the WP forum, but I haven't had much luck getting anyone to respond to my questions over there.

Can anyone help?

I found it! After searching in vain for "entering text from web" and search strings like that, then refining my search to "blogit", I remembered there was something that was called something like "blogmarklet" or something like that, but there wasn't. Then I tried "bookmarklet" and that took me to "Press This", which has been replaced in 2.6 by "Press It". In case anyone else wants or needs this information.