Hello there. I design/develop the occasional web application, and I frequently find myself needing to store data that connects two things together. At the moment, I just store one piece of data from each in it's own table, and use that. For example, a "friend" system where users select their friends (where they could have any number of friends). The system I currently use would simply store the ID of the user, and the ID of one friend, but this seems hardly optimal to me, especially since in a real life situation with more than 100 users, something like this would expand extremely quickly. Is this really the best way, or can anyone suggest an alternate method of setting things up?