So far, Facebook Chat is indeed rolling out slowly. Of my 130-odd friends, only 5 show up Chat-ready, but more seem to be appearing as the hours tick by. At first, the limited list makes for an uncompelling experience, but as all Facebook users gain access, the experience will change. Imagine: stumbling across a old high school friend on Facebook and immediately engaging in conversation. (Or, worse, immediately finding all about your college ex's wonderful new life.)
The Facebook Chat Web app itself is easy and straightforward. Look to the bottom-right corner of an open Facebook browser window to see how many of your friends are online and available to chat. Click their names and start typing. The most right-hand icon brings up your status window, where you can change your status to "offline" in order to avoid invites.
Facebook Chat's help page confirms the slow rollout: "We are currently running a pre-launch beta to a few networks to make sure that the product is ready to go. Once Facebook Chat is ready, we'll release the feature to everyone on Facebook." Even once Facebook Chat leaves beta, not everyone will have immediate access and some may never--currently, the Web app works only with Internet Explorer 7.0, Firefox 2, and Safari 2 for PC and Firefox 2, Safari 2, and Safari 3 for Mac.
If you're in one of the early rollout Facebook networks (so far, Harvard seems to be one of them. Any others?) and want to chat with many friends simultaneously, you can take advantage of the "pop-out" Chat window, which opens a small, floating browser window to better manage a lot of chatter. Unfortunately, however, the Web app only alerts you to new messages or conversations within its active browser window. There's no sound to alert you to new messages, so you won't see them until you pull up Facebook or your pop-out window. Nor can you block specific friends from starting chats, but Facebook says it's working on that.
Additional small complaints include: no compatibility with other, third-party chat clients; no platform integration for outside developers; and no party-line chat. Still, I predict the success of Facebook Chat is all in the (healthy) network.