Facebook has just released an updated iOS app version 5.1 that incorporates some features first seen in its standalone Camera and Messages apps.
From Facebook App Store:
Now it’s easier to chat with your friends and share multiple photos.
• Swipe left anywhere in the app to quickly see who’s available and send a message
• Add friends you message most to the top of your Favorites
• Share multiple photos fast
• Give real gifts to your friends using Facebook Gifts (US-only)
• When sending messages, see who’s active so you and your friends know how soon to expect a reply