WorkHappy is hosting a challenge: use Microsoft's $200 adCenter credit to launch a new venture. It's a great potential motivator, because the offer is available for only one month (until January 15).

We say use it whether you're starting a new website or you already have one. Like Google's AdWords, adCenter shows your ad next to a user's search results, and you pay for each time a user clicks through to your site (except during the promotional period, when the click just gets charged toward your $200 credit).