Now that I have one of those mega-zooms that goes from 18mm-270mm, I was looking to get specialized lenses for various uses.  I want to start with a portrait lens first.  A prime lens would do but I was hoping for somthing with a short zoom range like 30mm to 100mm or even 50mm to 100mm to better frame my subject.  Apiture of 2.8 or better, good sharpness and a reasonable price $500 or less. 

Any suggestions?

I'll second the recommendation on the Tamron 28-75mm f/2.8 lens.  On a DX sensor camera that functions as a 42-105mm lens.  That is a terrific focal length range for portrait shooting.  

That lens is extremely sharp and focuses very fast too.

Here is a link to my flickr account where I posted a set of portrait images I shot using that lens.

http://www.flickr.com/photos/stanjaws/sets/72157600724544392/