Add an option in the UCP to set how many posts per page you will get. Default is 15 for phpBB which is not big enough for me (I used 50 on vBulletin boards).
This will improve forum use because people can customize their look even further. Users with better internet connection can set up higher number while old-school dial-up users can lower the value.
Also, there is ready phpBB3 mod but I haven't tested it.
Vote please.