Review: HP Veer 4G
HP's developers have been hard at work integrating Facebook into the webOS platform. Most of the integration comes with the Synergy contact management application. It will import all your Facebook contact info even if you don't have the Facebook application installed.
Speaking of which, it isn't, by default; you need to find it in the App Catalog. The same goes for Twitter and most other social networking applications/services.
The Facebook and Twitter apps I found in the app catalog were decent, but not nearly as fully featured as what's available to the iOS, Android, and Windows Phone 7 platforms. They work, to be sure, but aren't are refined as what's available on competing phones.