Problem / Question: Where can i get "x" mod for phpBB?
Answer / Solution: I recommend you primarily look on phpBB.com either in the download database on their main site or by looking in the forums in the MOD categories. I discourage using BETA mods as these may have bugs and errors within them. The MODs on phpBB.com are checked over to make sure that they work and are validated and verified. On phpBB.com there is a special search engine for mods: http://www.phpbb.com/phpBB/mod_search.php
The other option is to go to the site phpBBHacks.com, which is a lot bigger and larger database. Whilst support may or may not be given on that site, it normally always is on phpBB.com by either the mod author or existing users of the mod. The search page can be found here.
Note - Some mods on this site are released on this site phpBBStyles.com - for that I recommend you go to search and search for the keywords using AND between key words to get a more accurate search. For example for the today and yesterday mod, search today AND yesterday.