public static string GetUa(HttpRequest hr)
    {
        try
        {
            string visitorBrowser = hr.UserAgent.ToString();
            string originalBrowser = hr.ServerVariables["X-OperaMini-Phone-UA"];
            string anotherOriginalBrowser = hr.ServerVariables["X-Device-User-Agent"]; //novarra
            
            if (!String.IsNullOrEmpty(originalBrowser))
            {
                return "OPERAMINI " + originalBrowser;
            }
            else
            {
                if (!String.IsNullOrEmpty(anotherOriginalBrowser))
                {
                    return "NOVARRA " + anotherOriginalBrowser;
                }
                else
                {
                    return visitorBrowser;
                }
            }
        }
        catch
        {
            return "No UA Found";
        }
    }

UPDATE: You can now download Opera Mini from App store! Apple finally approved Opera Mini for  iPhone!

Here are some screen-shots! Unfortunately it does NOT support uploading from iPhone

Opera Mini is ready for iPhone and submitted to App Store for approval. Opera put up a web page to track time it will take to get Opera Mini for iPhone to approve. As i write this post it already has been 2 days 19 hours and 41 minutes.

Here is the official video of Opera Mini for iPhone

"Opera Mini 5 beta for Android is finally here! Featuring all your favorite Opera features such as Speed Dial, tabbed browsing, compression, speed and a smooth design.

We know many of you have been waiting a long time to get Opera Mini for Android, so we're very excited to hear what you think of it!"

From http://my.opera.com/chooseopera/blog/2010/03/11/opera-mini-5-beta-for-android

Image source: http://wapreview.com/blog/?p=6640