- Pirates and Pals cruise - an evening snack party complete with a meet and greet with Captain Hook + Mr. Smee, followed by a "cruise" on the lagoon to a spot where the boat pauses, and pipes in the music, for Wishes. The view is great (although not up close, since you are, after all, out on the lagoon). Each boat has a guide (named Patch) who cracks jokes, asks trivia questions, gives out prizes, announces celebrations, etc. When your boat returns to the dock, a special "surprise" character greets your boat and does a meet and greet with everyone on it. We took our son, who was 3 1/2 when we last went. He loved it. So did the families with older (even teenaged) kids, and we also had a bride and groom on our boat, too. Basically, it's fun for everyone. We're debating doing this one again on our next trip, when my son will be about 5 1/2...
- If he likes pirates, would he enjoy a makeover at Pirates League? It's the boys' (and non-princessy girls') answer to Bibbidi Bobbidi Boutique - kids get a pirate makeover complete with facepainting makeup (of their choice), a pirate name, and special pirate pics. There's an afternoon "parade" of pirates around Adventureland in the MK that Pirates League kids are encouraged to march in, if they so desire. This is on our to-do list for our trip this year, I think...
- Pin collecting/trading. We started letting my son pick out pins on his first trip, when he was 2 1/2. For now, he just wants to collect them, but if he decides he wants to start trading, we're fine with that.
- For autographs, have you considered the Disney character encyclopedia? A new one is coming out fairly soon, though I'm not sure if it's before or after your trip. You can use this before the trip and on the drive to Disney to build excitement and familiarity with the characters, then use it as the autograph book once you're there. Characters can sign their page, if you run across someone who isn't in the book, they can sign inside the cover...
- Instead of or in addition to Sorcerers of the Magic Kingdom, you could try Pirate Adventure/Agent P's Adventure/Wilderness Explorers (based on which park you're at) - kids can go around the park and find "treasure"/solve problems/etc. It adds a little something extra to the time you spend in the park.
- If you'll be in the parks after dark, consider picking up glowsticks or similar light-up things locally - it'll cost a lot less than a light-up toy in the park!
- As for stuff for the drive down, you don't have to over-do the theme. Bring stuff he would typically enjoy doing in the car, with maybe one or two Disney variants. When we drove to Chicago with my son (at age 4), we brought a small-ish dollar-store cookie sheet that fit on his lap. He used that as a base for building with his magna-tiles and his magnetic Mighty Mind puzzles. (Which are AWESOME for travel!) Also helpful if you're going to bring things like magnetic checkers and other games.
I have done custom autograph books and tee shirts in the past for him but looking for a few new ideas to make his trip extra magical. Do you think a fairly shy boy his age would be into pin trading? Are those Mickey ears that light up with the show worth the money? Any other ideas? I'm trying to buy little gifts for our crazy long car ride down and want to get some Disney things ahead of time to cut down costs while we are there. 
