I was looking at the white space in <a href="http://www.programmableweb.com/matrix">ProgrammableWeb: Web 2.0 Mashup Matrix</a> and noticed that Skype has almost no entries. but then I looked at the other IM services and they don't ay entries either. So what is it about Instant Messaging that makes Mashups with other Web APIs difficult? Well IM is yet another Identity name space and is predominantly about people. And very, very few systems (with or without APIs) allow you to search for people or retrieve data based on their IM address. The limit seems to be just inserting IM links into people's profiles and maybe showing their presence information. And like IRC, developing bots that embed some external function into an IM chat conversation.

I notice that MSN is still running a competition for the best robots. http://www.robotinvaders.com/main/HowToCompete.aspx Maybe Skype should do something like this as well. There's very little I've seen in the way of Bots for Skype chat.