When asked to create system XYZ and you ask to do it in Python over PHP or Ruby, what are the main features you can mention when they require you to explain it?
It's one of the preferred languages over at Google - It's several years ahead of Ruby in terms of "maturity" (what ever that really means - but managers like that). Since it's prefered by Google you can also run it on the Google App Engine.
Mircosoft is also embracing Python, and will have a v2.0 of IronPython coming out shortly. They are working on a Ruby implementation as well, but the Python version is way ahead, and is actually "ready for primetime". That give you the possibility for easy integration with .NET code, as well as being able to write client side RIAs in Python when Silverlight 2 ships.
How to sell Python to a client/boss/person