Can you upload programs you write to the iPad without involving the Apple store?
Yes, there is Ad Hoc distribution that lets you install your app on 100 iPods or iPads. There is something similar for corporations which allows more than 100 devices.


  Ad Hoc Distribution
  Share your application with up to 100 other iPad, iPhone, or iPod touch users with Ad Hoc distribution. Share your application through email, or by posting it to a web site or server.