A couple of weeks ago, we posted our solution to cross-platform Skype calling from within a Filemaker database. We were pretty pleased with it for our database solution as it allowed us to utilize our Skype subscriptions directly no matter whether we were using a Mac, PC or iPhone. But it wasn't quite perfect.
So, we've worked on it some more and now it will send a SMS from Skype, and if you're on an iPhone it will send a SMS using the Message app and make a call using the Phone app.
Check out the solution attached, and a PDF of the script as well as the attached demo file are available here: http://www.soundsessential.com/blog/42-information-technology/filemaker/72-filemaker-pro-cross-platform-skype-part-2-sms-iphone-calling
Again, hope this helps with your solutions.