Although the SQL Azure Data Sync Service is currently free, it does require you to have at least two SQL Azure databases to sync your data with. Until now, there was no free version of SQL Azure to allow you to get started. That has now changed as Windows Azure has started a free one month trial of Windows Azure. Using this link, you can register for a one month pass to try out SQL Azure and Windows Azure - without having to submit a credit card. This is a great way to give the SQL Azure Data Sync Service a try without having to make any financial investment.