This plug-in hides a specific part of the content of a page (or post) to all users whose user level is below a required user level.

Therefore, if a content is visible to user level X:
1. if X > 0 users who are not registered will not be able to access that specific content;
2. users whose user level is less than X will not be able to access that specific content;
3. users whose user level is equal or greater than X will be able to access that specific content.

To hide a specific content, use the following syntax to encapsulate the hidden content:
[hide {level}] {content} [hide {level}]
where {level} is the NUMBER corresponding to the user level, and {content} is the part of you want to hide.

Example:
[hide 0] You will always see this content [hide 0]
[hide 1] You will not see this if you are not logged as subscriber [hide 1]
[hide 2] You will not see this if you are not logged as contributor [hide 2]
[hide 3] You will not see this if you are not logged as author [hide 3]
[hide 4] You will not see this if you are not logged as editor [hide 4]
[hide 5] You will not see this if you are not logged as administrator [hide 5]

Fancy example:

[hide 1] You will see this if you are logged as subscriber [hide 5], but you will not see this if you are not logged as administrator [hide 5][hide 1]

Download the plug-in from here