You can't modify your code, but you can modify your php.ini?
OK.
PHP has a very nice feature where you can automatically prepend (and append, if you want) a file to all requests. Create a single file, modify your php.ini, done.
I am not telling you that eaccelerator isn't amazing. I am showing you how to get around problems you may run into if you end up using a different op-code cache.