If were just throwing out concept ideas here, yes a database would be great to do that type of cross referencing...The cool thing about doing somthing like this you could easily make an interface like a search engine that is almost like a frontend to the database...somthing where you could do simple sql queries like "select hostnames,urls from database-name where hostname like .de sort by urls". Somthing like that could easily be put into a frontend cgi script that had a bunch of drop downs and stuff...The only complexity to this is deciding how you want to sort your tables. The acctual frontend is simple dbi stuff.