funambol.
Free open-source over the air sync solution, sort of like an el cheapo Exchange Server, or BES.
Basically, install the client on one phone, all your pim is pushed to the server. Install the client on another phone, all your pim is pushed to the new phone.
What's great about this is that you can keep two totally different devices in sync if you ever switch back, or if you're like me and swap handsets on a whim, but want all your stuff in sync on everything.