Yes, you can get a birthday pin at City Hall in MK. This will get all sorts of recognition & special attention from the CMs. It never hurts to casually mention special events like birthdays & anniversaries. I know a CM there who makes it a point to bend over backwards upon discovering anything special about guests at the park & many others feel the same way.
You'd be surprised how much all of the "little things" can add to a WDW trip. A few ideas:
1. Purchase a park photo album & some of the offered photos (from character meets, park entry, attractions, etc.) Put all of these, along with your standard photos in the album & you will have a personal momento. I always take about 10 rolls of pics to make sure that I caught everything, often snapping double pics to make sure they come out ok. I also grab park maps, napkins, room keys, park passes, etc. & add all of that to the album as well. Include photos at: the sorcerer hat, the castle, the Partners statue, Spaceship Earth, the Tree of Life...just to name a few. If taken well, these are even nice to blow up & frame.
2. Make sure to take time out for often overlooked things: the Dapper Dans at MK, the Living Statues at EPCOT, street performers at MGM.
3. Sitting on a bench & enjoying a snack is a great way to just relax & observe everything going on around you...especially if you're going with kids & can do this near the water play areas!
4. Storytime with Belle at MK.
Just a few ideas. Bottom line...notice the little things. People overlook so much at WDW in a rush to get to the next ride line. These little attractions are often easy (no crowds of people) & create the best memories.