If you check your user page, you'll find a new accounts tab.
Here, you can associate your accounts between all the 'family' of sites we now operate:
The associations, once made, are public and visible for anyone to see on your profile -- so people can follow your 31 pieces of flair to another site and check out your questions and answers there as well.
All very good, but here's the exciting part: there is a +100 reputation bonus for every association you make, if either the source or target account in the association has at least 200 reputation. An account can have a 100 point bonus awarded for being in the same "network" of associated accounts if any of the associated accounts has 200 rep or more. This bonus is only awarded once per account -- so if you associate four accounts, you'll get +100 reputation on each site. This is intended to give established users a "leg up" when we start new sites, so they can have an account with 101 rep instead of the default 1. But wait! It gets better! This also works with Google's per-site hash OpenIDs, too! (Note that if you have only a Google OpenID, you may be redirected to log in to the target site depending on what cookies you hold.) Now go forth and let the associating begin! Update: We now have "Copy Profile from {site}" and "Clear All Associations" buttons on the accounts tab as well.