I became pretty friendly with Elijah's former day care teacher. She has invited the boys to her son and daughter's combined birthday party. Daughter is a toddler, so no problem there, but what would you get the son? I have met him once and he was a polite, quiet kid, but other than that, I am not sure about anything that he is in to.
I would prefer not to get a gift card, but will if no other ideas surface.
My son and his friends like anything from a sporting goods store. Footballs, hockey/baseball/football cards, gift cards, knee hockey sticks...essentially anything sports. Obviously you would need to know if her son is into sports or not though! Also, rubix cubes are a big hit in my sons grade right now!
DS1 also likes Quirkle, Battleship, Clue, and Traffic Jam a lot. He got a Magic 8 Ball and Would You Rather cards in his Easter basket and has had fun with those.
Books of strange records and facts (Guiness Book of World Records, Ripleys Believe It Or Not books, sports trivia books, etc.) seem to be popular with his crowd.
A very sweet 10 year old boy down the street just gave his old Power Wheels to my boys. I asked his mom what kind of gift card he would like as a little thank you, and she suggested iTunes or Amazon.