What options are there currently for displaying business charts (e.g. bar, pie, scatter, line) in a MonoTouch application? Obviously I could roll my own using the graphics library, but are there any existing MonoTouch-compatible libraries?
If not, could I use a standard iPhone charting library in MonoTouch (i.e. something designed to be used with ObjC and Xcode)? Are there any good tutorials for learning how to do this - e.g. calling a commercial iPhone UI library from MonoTouch?
For simple charting, any open source C# library that doesn't depend on special frameworks, like ASP.NET or winforms should work just fine. As long as the library can create png or gif images, it should work. I'm currently using the Google Charts API for a simple project, which instead of creating the charts on the phone, I just download them from the web. It works great for me.
For more advanced charts made in C#, I think you (and I) are currently out of luck. I haven't found anything yet that uses UIKit directly with animations and events.
You can load an obj-c based library, although that is not as simple as loading c# code. You'll need to create bindings for your library, if those do not already exist. Novell's documentation on it is pretty good: http://monotouch.net/Documentation/Binding_New_Objective-C_Types