Thanks and its good to see that you are following my blog well and now about using Aweber in phpBB is very much possible because Aweber works well with any HTML page and so you do not need to anything fancy to use it for phpBB when it comes to putting up the forms.

Now When it comes to Registration integration with phpBB Aweber here also has general solution and I have mentioned the process under the section "Full Use of Aweber"

If you have further question do fire them.