1. VoIP User Presence by Dean Elwood
Dean's a friend who runs VoIPUser.org (and provides the SIP voicemail box for Blue Box comments) and he's been experimenting with the Facebook API. This is the first of what he says will be a series of Facebook apps. Dean says this one is "SIP meets Presence meets Google Maps" and provides this on the Facebook apps page for a description:
"This application shows within your profile if you have a SIP device currently logged into the VoIP User server and are available to take calls. The application page also shows a Google Maps mashup page showing your current location."
There is also a thread going on in the VoIPUser.org forums about the application with more info, screenshots, etc. It will definitely be interesting to see what else Dean cooks up.
More feedback on this one once I have a chance to actually use it.
2. Skype Me by Nabil Naghdy
This one does the rather obvious and lets you see the Skype presence of your other Facebook friends (provided they have installed the application). With a tagline of "skype meet facebook. facebook meet skype." the developer says on the FAQ:
"SkypeMe is a Facebook application that links with your Skype account and lets you make calls right from inside Facebook. You can see which friends are online, make calls, and even buy SkypeOut credit from Facebook."
It appears to work primarily by getting the web presence of each of your friends and making that available to you, which means, naturally, that you need to enable Skype web presence inside the options of your Skype client.
There's actually two parts to it. On your public profile page visible to everyone else, there is a box like the image shown on the left that lets another Skype user initiate a call to you. On the internal page inside of my Facebook account for the applications I have installed, there is a page with a screen like the graphic on the right that shows all the Facebook friends I have who have also installed the SkypeMe Facebook application.
This Facebook app was announced in the Skype Mashup public chat. Actually, I think it was really the first I saw announced (but then again, I wasn't really watching the chat last week while I was off).
Speaking of the Skype mashup contest, it was officially announced last Friday. It will be very interesting to see what developers come up with!