What is a good hobbyist’s programming language?

For a long time I have wanted to learn to write computer programs, mainly to write functional apps. I have a pretty decent understanding of how computers work. Years ago I messed about with VisualBasic.NET which was OK for writing simple productivity tools on Windows, but A) I’d like to eventually move beyond productivity tools and B) I’m on a Mac now.

I probably won’t ever write the next Adobe Creative Suite, but I would like to make smaller, simpler apps, like note taking software, a simple multitrack recording program, a simple image editor, etc.

One more thing, due to real life obligations, my time is limited. I am not able to spend many hours on end daily studying. Now, what cross platform (or at least Mac OS X compatible) programming language is relatively (I repeat, relatively) easy to pick up?

P.S.: I would like to actually be able to use it within a year, because from then on I’ll have even less time.

Ruby is great and fun.
Python is like the king of C,UNIX now.
Look at any good program, it is Python or C. and usually free.