The following nasty sql will create ptr records for your zone files from the ser subscriber table. It works on the assumption that all your usernames are only 4 characters long, and they are infact numeric...

select concat(reverse(insert(insert(insert(username, 4,0,'.'), 3,0,'.'), 2,0,'.')),'\tNAPTR\t100\t10\t"u"\t"E2U+sip"\t"!^\\+',username,'$!sip:',username,'@',domain,'!".') AS PTR from subscriber where username REGEXP '^[0-9]...$';

If any one knows how (in sql) the hell I can put a '.' between every character of a mysql result when the data length is variable then I'd like to know :)

Regards, -Jev