For those interested in using Gambit on the iPhone/iPad/iTouch, I have created an example (examples/iOS) which shows how to do it. One of the key components is the "build-gambit-iOS" script, which builds the Gambit runtime library for the physical device, and the simulator.
The app, which is called "Gambit REPL", offers a simple development environment for Gambit. It is possible to interact with the interpreter/debugger using Gambit's REPL. A collection of scripts can be edited and run. The program comes with a few predefined scripts, including a REPL server which allows starting a REPL from a remote telnet client.
Below are some screenshots for the iPhone.
I may be submitting this to the Apple App store. If you fiddle around with the app, and improve it, have comments or write interesting scripts, please let me know and I will add them to the app.
Marc