Need help in deciding a Wide Angle Lens for D7000

Hi,

I am based out of Los Angeles, US and I own a Nikon D7000 and have the below lenses with me
1. 18-105mm f/3.5-5.6 AF-S DX VR ED Nikkor Lens (Kit Lens)
2. Nikon 50mm f/1.8D AF Nikkor Lens

I am looking to buy a new Wide Angle Lens.

I would like to have experts' opinion here and it would be great if you can suggest me a good Wide Angle lens in the budget $ 400 - 700.

Thanks in advance
Vishal

Feel free to look at my Flickr - http://www.flickr.com/photos/vishucool/ and give your feedback/suggestions