Be VERY CAREFUL doing this in a production setting. Items in a web server's error log could easily contain very privileged information, including database usernames/passwords, or snippets of code that could contain other sensitive information. Additionally, this opens you up to some cross-site scripting vulnerabilities. I would be very wary of doing something like this on a production server. Remember that the "last few lines" of your error log could easily be output from another script!

If you're just trying to debug your CGI scripts, consider using CGI::Carp to do this. I'd still turn this off on a production site, though.