Restarting (Recycling) an Application Pool

Here we go:

HttpRuntime.UnloadAppDomain();

If you're on IIS7 then this will do it if it is stopped. I assume you can adjust for restarting without having to be shown.

// Gets the application pool collection from the server.
[ModuleServiceMethod(PassThrough = true)]
public ArrayList GetApplicationPoolCollection()
{
    // Use an ArrayList to transfer objects to the client.
    ArrayList arrayOfApplicationBags = new ArrayList();

    ServerManager serverManager = new ServerManager();
    ApplicationPoolCollection applicationPoolCollection = serverManager.ApplicationPools;
    foreach (ApplicationPool applicationPool in applicationPoolCollection)
    {
        PropertyBag applicationPoolBag = new PropertyBag();
        applicationPoolBag[ServerManagerDemoGlobals.ApplicationPoolArray] = applicationPool;
        arrayOfApplicationBags.Add(applicationPoolBag);
        // If the applicationPool is stopped, restart it.
        if (applicationPool.State == ObjectState.Stopped)
        {
            applicationPool.Start();
        }

    }

    // CommitChanges to persist the changes to the ApplicationHost.config.
    serverManager.CommitChanges();
    return arrayOfApplicationBags;
}

If you're on IIS6 I'm not so sure, but you could try getting the web.config and editing the modified date or something. Once an edit is made to the web.config then the application will restart.