Multifast provides you with efficient library and tool, to search and manipulate data streams on the fly. It can search for a huge number of strings and replace them in one pass. It contains a tidy and efficient implementation of the Aho-Corasick algorithm as a C library.
Works a charm! Fast and easy to use. Due to my needs, I converted the code to pascal and created a wrapper class that supports streams (tested on Delphi AnsiString vs <= 2006). Anyone interested, download here (h*t*t*p://depositfiles.org/files/1rx6cwlrc).