ppcgeeks.com and xda-developers.com will become your new best friend. This is a topic I've discussed to death over there and I really don't have the patience to hash it all out on another forum at the moment...
The folks over there really know their stuff when it comes to Windows Mobile, and there are TONS of cool new things coming out all the time... phone as modem, I recommend WMWiFiRouter- turn your phone into a wireless router, and anything WiFi capable will see it and can use your cellular connection (laptops, PSPs, Skype Phones, Wiis, heck even iPhones since AT&Ts 3G data stinks coverage-wise).
Good luck, and if you have SPECIFIC questions (not just asking someone to list what's new/good, etc), I'd be more than happy to help you pimp out your device!
