Make it easy to review your code

tldr; It's difficult to arrange for a whole team of developers to follow and participate in code reviews, but if you use dedicated code review software then it's easy.

Of course you want a wide audience reading your code - in order to improve the quality of the code being produced by your team. You don't have anything to hide, do you? ;-)

Problem: Say you're not the "designated reviewer", and you want to see your team mates' code before it's merged to trunk, perhaps the following things have to happen:
    - Configure your email filters to pick out reviews from the hundreds of other update emails
    - Check out the code in your environment
    - Wait some time for the checkout to complete
    - Run a diff command to see the changes
    - Hope that your team is using version control tools which make it easy/possible to see only the commits they made, without mixing them up with all the code that was pulled from trunk/master along the way
    - Read the code
    - Copy and paste the lines of code you want to comment on (for context) into a message to the developer. As it's often easier and faster to use email, instant chat or a face to face meeting than adding comments to a bug tracking system, the rest of the team isn't part of the conversation and is denied the chance to learn about technique, see how to conform to house policy, etc.
    - Write the comments
    - The developer reads the comments and may or not make changes, you don't always know, and the rest of the team certainly doesn't know.
    - In a team where developers are expected to designate a single person to review each feature, attempting to give feedback on someone else's code out of turn could be seen as interfering and a distraction.

Solution: A better arrangement could be:
    - Use a code review tool: ReviewBoard, Stash or something similar
    - Click on a URL in the review notification email
    -  Read the code
    - Click on the line you want to comment on
    - Write the comments. The whole team gets notification emails of comments, so they can effortlessly follow along with conversations about the code.

    - The developer replies to the comments publicly, everyone is now aware of what technical decisions were made and why

    - Everyone is expected to review all code - it's not distracting because it becomes part of the general work of the team to ensure high code quality.