Microsoft wants to give two Kentucky Derby fans Nokia Lumia 900s as part of this year’s Run for the Roses. Ramon Dominguez, who will be in the Derby atop Hansen, the current favorite, will be wearing the Windows Phone logo on his silks.

Hansen is a bit unique, in that he is the only white horse to be entered in the Derby this year – or in the past several years, for that matter. As part of their sponsorship, Microsoft will also be giving away two white Lumia 900 smartphones. To enter, you must have a Twitter account and follow the official Windows Phone Twitter account. All you have to do is send them a tweet with the hashtag #TrifectaTweet with your trifecta (which horses you think will come in first, second, and third).

Fortunately, you don’t actually have to get the trifecta in order to win the contest. In fact, according to the official rules, you don’t technically have to list your trifecta at all, you just have to send a tweet with the hashtag. Entries are limited to one per person and Twitter handle, so don’t bother spamming them with lots of tweets.

You can enter any time between now and 5 PM Pacific time on Saturday, May 5th. The winner will be randomly selected around the end of the entry period and the two phones will be delivered sometime within the next 4-8 weeks.

The 138th Kentucky Derby will be run on Saturday, May 5th.