I've gotten a fair amount of practise in Obj-C programming and I'm looking forward to building some Apps that will run on my iPhone and Mac. They've built the richest developer's environment possible. There's a lot to like about OS X.
Persia,
Anubis is going to be heavily Objective-C based, and I'd love to invite you to join our project, especially if you have Objective-C experience. For those of you who have not had much or any exposure to Objective-C, feel free to visit
http://gnustep.made-it.com/BG-objc/index.html or pick up a new or used copy of the book "Programming in Objective-C" by Stephen Kochan (
http://www.amazon.com/Programming-Objective-C-Stephen-Kochan/dp/0672325861). This book presumes no previous experience with C or any other programming languages, and covers learning Objective-C under both OS X and Windows, using GNUstep.