Anyone knows any application that will allow me to share my OS X Lion screen with an iPhone? I don't care to have it over the Internet, WiFi is sufficient.
The title of the question says iOS, so here's an iPad solution.
I use DisplayPad (currently $2.99 USD). It's great because it's got close to zero configuration parameters: it just works. My Mac treats the iPad like a second monitor.
It doesn't work on the iPhone as far as I'm aware.
I recommend the free app VNC Viewer by RealVNC, available on iOS, OS X, and Windows. The app is barebones and the icon looks from the 80s but it works perfectly, simply, fast, and, it's free.
I don't recommend TeamViewer, it requires you to run another piece of software at all times on the sharing computer, and can cause heavy resource usage on that computer, in addition to causing other major bugs (it did for me anyway). The only good thing about it is that it can share audio, which VNC does not do.
Just open the app, create a new profile, and put in your mac's IP address. (Also, you must enable screen sharing in the mac system preferences/sharing if it's not already.)
You can also access remotely if you forward the VNC port (5900) to your mac in router, and signup for a dynamic dns service (free to set up with some routers), this can be very useful sometimes.
Teamviewer app works great. You just register a user name and password, add a device via a code from the teamviewer app you installed on it, and voila, it works. I have this on most of my gadgets, and each one can see the others.. well, the mobile apps can interact with the PCs/servers/laptops and so forth.
Oh, and it's free for home use, works over wifi or internet/remotely, with no need for port forwarding or anything.