I’ve recently noticed a few bloggers these days, including one on LockerGnome that was for some reason recently praised by Chris Pirillo, that take a lot of text from other web pages, and pastes the text into their own blog. On some occassions, this is fine if you are discussing a point. You want to include some of the text you are blogging about. On most occasions though, I see that people posting lots of text that other people have written.
In my opinion, this is just plain lazy and poor blogging. When 75% of your post is stuff you copied and pasted from somewhere else on the web, it’s probably not worth posting. Use your own words! If you’re going comment on something somebody else said with one or two sentences, do us all a favor and just post the link to the page where the original owner of the content posted the material, and comment on it there.