You can also use ExpertFlyer (paid, but they do offer a few days free trial). UA award space can be found using this tool. Or, you can search for flights on ual.com using miles even if you aren't logged in (e.g., if you aren't a member of MP). I just checked it out, it works. You can't book this way, but you can find flights with award space, and then call M&M to book your *A award.