A clique, as we all know, is a group of tightly woven friends who pride themselves on simply being together at the exclusion of everyone else. The only thing more uncomfortable than approaching a clique (usually a group of giggly or snobby girls and self-intoxicated guys) is being shot out of a cannon directly at a brick wall. Had I only been shot at brick walls as a teenager, I might be a little happier today.
I've noticed that friendships in general are a lot easier to form and maintain for guys than they are for girls. In fact, you can punch guys in the gut repeatedly and they don't really mind as long as you share your football tickets with them. Men and boys as a whole are more forgiving than girls, and generally avoid arguments.
Even so, guys still have to deal with cliques and "in-crowds". Guy cliques, or "Ego Central", are almost always made up of guys with similar interests who grew up together. So while you're trying to bring up a new topic for conversation, they're still reminiscing about the same unbelievable Nerf football game they played in kindergarten.
Such groups will form around similar interests both in and out of school, so unless you are always where they are, you have little chance of being included.
But why would you want to be? Besides for limiting you socially, you are never given a chance to shine as an individual and build your own character.
You're known as "they" and never as "he".
The best advice I can give you is to stick with your own friends and never form an impenetrable "fortress of insecurity" yourselves. Though what "they" are doing seems to be getting a lot more attention now, time will show the value of your friendships over theirs.
Even without traveling in trendy packs, guys and girls will vie for each other's attention as individuals, as well. The way some people act in order to boost their popularity, you'd think that they were getting paid. Joining the basketball team and being a bit more outspoken is one thing; acting completely out of character and breaking all the rules just to be "popular" is something else altogether.
Many times guys will do crazy things to give their ratings a jolt, but the satisfaction fades fast and the moment of fame sometimes leaves months of work to repair the damage done. Trying to be someone you're not can only hurt you and your relationships, and will rob you of whatever respect others had for you to begin with.
Friendships that are developed over time, are based on honesty with one's self and with one another, and are not forged just to exclude others, will be a lot deeper and more fulfilling than any clique that ever was or ever will be.