okay, so I want to target keywords "free essays" script that is responsible for categories etc runs as essays.php SEO-wise is it better to change that to free_essays.php too?
yeah, I think its relevant... I updated my script to contain keywords in filenames... hope that helps with SEO I see google uses tittles too, it seems as if its one of the important issues with google :S
Yeah, there was a write up by matt cutts on the hyphen-underscore topic as well in which he says that hyphens are definitely better.