Win prizes all day long

To celebrate our 10th anniversary we'll be giving out a prize every hour for 24 hours on Twitter. Here's a quick guide to help you get in on the action:

1. Contest runs midnight to midnight on April 7, 2010. This is using Mountain Time.

2. You have to follow @iStock on Twitter to win.

3. Starting at midnight we'll tweet instructions on what you have to do to win that hour's prize. All entries must include the #iStock10 hashtag. You can only enter once per hour.

4. Winners are drawn at random each hour from qualifying entries. Shortly after the hour ends we'll announce how to win that prize. Entries do not carry over hour to hour and you can only win once.

5. We've pre-determined the order we'll be giving out the prizes in, but we aren't telling you what it is. We have divided them evenly across the day so all time zones get a fair chance at winning the really good stuff.

6. There is a fairly lengthy “official rules and regulations” that we suggest you read. Many, but not all, countries and territories are eligible for this contest.

Follow iStock on Twitter