On CNN's iReport, they've set up a page to help people look for and find loved ones in Haiti. Thankfully, they've added a search function to make the process much easier.
It's kind of slow and you may get error pages - likely due to timing out. There are probably so many people trying to use the tool, it's going to take awhile to get your info.
Also, it will automatically add in the words "haiti earthquake" to your search query. This is likely due to the need to filter down the search to relevant pages - as iReport involves information beyond the Haiti earthquake.