I love the charm bracelet idea...I had one when I was little and it represents all chapters of my life. I don't wear it much as an adult so took the charms off to wear as pendants..I change the necklace charm as my mood changes. I wish I hadn't done it though, the posts below remind me how much I loved it.
Since I forgot all about the charm bracelet, when it came to a "collection" for my daughter, we started a snow globe collection. It's nice, they represent a chapter in her life for each one...her first was a beautiful Winnie the Pooh, we have a couple Disney princesses and as she got older, they phased into some beautiful ones as well as some whimsical ones. It's a pain to store but lovely to look at...we take it out each year in her birthday month. Some of the favorites claim shelf space year round.
As for the charm idea, I did incorporate it for the "Tooth Fairy"...Every time she loses a tooth (we're not quite done yet) she gets a bead/charm to put on her necklace that the TF left for her the first time.