BigBoss has made a post to help developers compile their applications simple and easy using their iPhone and Itouch

Toolchain is the name of the compiler used for all the apps you see today for the iPhone. Historically, it has been very difficult to setup and get working often requiring several days of work. iPhone developer Saurik has created a version of the toolchain that runs directly on the iPhone. I have taken his toolchain which consists of his ported GCC and odcctools, and added my headers from the Cygwin toolchain that I use to compile my apps. Together, this brings you a one-click compilation environment that runs directly from the iPhone!

Here are the steps to install and start compiling your apps:

1) Install Cydia
2) Install “iPhone 1.1.1 Headers”
3) Copy your apps source code to /tmp or such with ssh and type “make”.

Works for all apps for 1.0.2 - 1.1.4. Will be updated for 2.0 after July 11th.

Here is a sample makefile (this is for BossTool obviously).

For more info about Bigboss go here