Your cousin is graduating from college/university? or high school?
For your brother, I\'d suggest a nice dinner out to celebrate. If he likes a certain movie, you can find out if you can find the poster online. It\'s ok to say that it\'s coming in 4-6 weeks. I had celebrated my b-day a few weeks ago and am still waiting for my sister\'s present that she bought on ebay. What does he like doing? If he has some hobby that requires supplies, you can get him some good quality stuff for that. Treat him to an amusement park.
I\'ll probably be back again, to suggest some more ideas.