I would say a PM to the person you are quoting, ask if it is ok, and a link back to their blog/homepage etc would be good.
I quoted a couple things from a post i wrote, and i still referenced it back to the forums. I quoted someone elses repsonse as well, and i made sure i got their ok via PM to do so.
The reason i say this is because what someone writes is their thoughts, opinions, etc. I feel they should know where their writing ends up. On the forums, if someone wants to delete their post, they can, but when you quote them, you take away their right to do such.
Just my two cents..
Adrienne
