Join the Developers Connection ... http://developer.apple.com/ . U will need the iphone SDK . it is pretty easy .... we have a custom ssh client we run on our iphones for work ... I have a php developer on my team that does it all for us and he finds it easy.
The two WWDC's by Apple have been all about the iphone.
I've been tempted to download this and try it myself, I've not written a program since school ( in the 80s) in COBOL so it may be a bit of a shock for me....