Visualforce Field History is a visualforce component and apex classes for reading the rather cryptic and undocumented __History tables generated by salesforce for tracked field changes, as well as objects being created that have a lookup field pointing to this object.
It as of recently can also include chatter tracked changes in the history listing.
If you want to help, think about adding support for pulling in chatter tracked field changes as well.
This repository is avilable under a BSD license for use.
History component in it's default state dropped into a visualforce page: