Its possible to add new file search engines like :

Proisk

http://proisk.ru/?debug=&help=&complex=&distinct=&live=&live_mode=&q=%s&accurate=&search_prev=&prot=prot&host=host&path=path&name=name&ext=ext&type_mode=&type=&size_mode=&size=&search_days_mode=&search_days=&gluel=&order=&page=&glueg0=&q0=&prot0=prot&host0=host&path0=path&name0=name&ext0=ext&type_mode0=&type0=&size_mode0=&size0=&search_days_mode0=&search_days0=&gluel0=&order0=

Mammont

http://www.mmnt.ru/int/get?st=%s

And support for filesharing services like rapidshare etc.