Answer:
I would use a manually created blacklist.
Filters like those found in Internet Explorer and Netscape can help users block out objectionable or obscene material. In this situation, I could add my own web addresses to the list of blocked sites.
Another method of filtering would be to install hardware-based filters that look for certain keywords in a user's browsing history and flag that information as unacceptable. This would give me more control over what is blocked, but again would not allow me to personally review each page flagged by the filter before it became available to students.
I would go with a manual blacklist because it will provide an extra level of protection to the computer lab without being very cumbersome or prone to bugs.
Step-by-step explanation:
My own original answer.