This mod actually works on 4.x as well you just need to rename the database table because VB4 already has one called "searchlog" and there's some SQL queries that need to be updated to the new name...

I made these changes for you... The attached zip has a new product.xml file and a new searchlog.php file... replace the files in the original mod with these and follow the install instructions... absolutely no code was changed other than the database name (to searchlog2) so this is still completely the original coder's mod. You could make the same changes with a text editor and search and replace if you want. If the original coder wants this will be removed, but all credit still goes to him for this useful mod.