[barista]

It's actually called list. Groups in FB is something different. Try creating a friend list and then you can share it with only that list.

[sandipagr]

You can't share with lists alone. Facebook sharing options are friends, friends and networks, Friends and their friends and so on. Or you have to add each friend individually. It's just weird how lists are pretty much useless in facebook.

[0x0]

Sure you can. In the status update thing, click the padlock and choose "Customize" and then "Specific people", and you can enter lists of friendlists.

(Granted, it's not very discoverable)

[smackfu]

Yep, my default sharing option is "Friends Only; Except: Work"

Only bummer is that you can't do fancy options like that with the Facebook iPhone app. You can only do your default, the normal options like Friends Only, or specific groups.