The problem with not being able to see the Slingbox Mobile for Andriod are filters within Google's Marketplace. If you're using an unsanction operating system, or are from one of the countries that do not currently support paid application then you won't be able to see it within the marketplace. This is because the Slingbox Mobile is a paid, copy-protected application.
Available per country (http://www.google.com/support/androidmarket/bin/answer.py?hl=en&answer=143779)
Unavailable per country (http://www.google.com/support/androidmarket/bin/answer.py?hl=en&answer=138294)
Work around for Froyo Users (http://www.androidcentral.com/how-get-your-paid-apps-back-froyo)
Work around for non-rooted phone (http://www.google.com/support/forum/p/android/thread?tid=441baa3452369f21&hl=en)
Work around for rooted phoes (http://www.google.com/support/forum/p/android/thread?tid=2a55855a017b346c&hl=en)