Anonymous Search Results

there is one page that is absolutely necessary for everyone to access: osssearchresults.aspx. This page presents the list of search results.

By default, viewing this page requires a user to be authenticated to the server. This can create a problem when your site definition includes the basic search control as it will attempt to render all search results on this page with Anonymous access.

locate the following text at the top of the osssearchresults.aspx (inside the < % @ Page ... /> declaration) and remove it:Inherits="Microsoft.SharePoint.WebControls.LayoutsPageBase"This setting determines the inheritance of the page from the generic application page base class; however, it is not required for the page to function. Anonymous uers will be able to view the page without having to login and search results will continue to be security trimmed so users without proper permissions will be unable to view restricted items.

this is from The SharingPoint it works fine and here you are the link below.

http://sharingpoint.blogspot.com/2007/05/anonymous-search-results-in-wss-v3.html

Anonymous impersonation for FBA portals in SharePoint

We all get used to grant IUSER_computername any access we need as IUSER is the internet users that all anonymous user are impersonating when they try to access any page in your portal, and it works for only windows authentication. To do the same thing but with forms based authentication you need to
1- Store or register your IUSER for example guest to your membership repository.2- Grant that guest any access rights you want inside or outside SharePoint.3- Write some code to make all unauthorized users impersonate that guest inside the portal 'Global.asax'. which is protected void Application_AuthenticateRequest(Object sender, EventArgs e) { string cookieName = FormsAuthentication.FormsCookieName; HttpCookie authCookie = Context.Request.Cookies[cookieName]; if (authCookie == null) { FormsAuthentication.SetAuthCookie("guest", false); } }So all the anonymous users will have a guest access 'your created guest' on your portal
For more details see the link below.
http://blogs.devhorizon.com/reza/?p=508