Customize SharePoint Search Control style

http://www.thesug.org/blogs/kyles/Lists/Posts/ViewPost.aspx?ID=12

http://erikswenson.blogspot.com/2010/01/change-sharepoint-search-icon-with-just.html

Create Custom Layout pages for WSS 3.0

http://wsslayouts.blogspot.com/2008/06/layout-pages-for-wss-30.html