Web Server Controls, Custom or

I'm relatively new to ASP .NET. While using all of the existing Web server controls available in the VS Designer I find myself wondering where are the fancy controls you see on some of the public web sites, such as Buttons with rounded corners, Tabbed pages, menus, etc. Do they have to be created as Custom Controls using the GDI ? Where does Dreamweaver fall into this issue? I have seen a few articles talking about the new version of Dreamweaver being used with .NET. Could anyone point me in the right direction to find out about using or creating these controls.
Thanks
CodeHead.
Well dreamweaver is nothing but an editor, which means just like FrontPage, or any other text editor that supports asp.net tags.
regards

Alot of the controls you are looking for are freely available. the microsoftInternet Explorer Controls for example, which include tab, treeview etc. Same goes for menus like theskmMenu and my own favorite theexcentrics world controls. All of these are free and can easily be put on your page.
Thanks to all, especially the links to all of the controls. Very Helpful !