Microsoft will pay you to searchSeachPerks. For each search you conduct on Live search (on Live.com or MSN.com), Windows Live Hotmail or Windows Live Messenger you will receive a ticket (up to 25 per day).
On April 15, 2009, the end of the promotion, registarants can trade their tickets for prizes like music downloads, cookbooks and airline miles. All users need a Windows Live ID. According to LiveSide's blog, up to 250,000 participants will be allowed to enter the program.