A website to create wikis (with mobile interface)

I want to have a website where people are able to create wikis. There are many examples of this website. The best example I like is Google Sites. It allows people to create both public and private wikis. Please consider it as a good model. I want some additional features for my own website: 1) When people are inputting text to the wiki, I want them to use some special operands in twitter style. For example, let's say I am writing to my wiki the following sentence: "Today, I had lunch with @MikeJones". When I input this text to the wiki, I want the wiki to automatically link "@MikeJones" to the wiki page named as "MikeJones". So, the information in the wiki will be linked. 2) I want an iphone interface. Biggest downside for Google Sites is there is no mobile version. I want my website to have a iphone browser version. These are the only differences. So, in summary, I want the following: Google Sites + twitter-like operands + iphone browser version.