Hi,
ActiveState do a good Perl package and I guess their Python one should follow along the same lines. It's free too as far as I know.
You might also want to have a look at Perl and Ruby. I found Perl to be very good and the same code (with a few exceptions such as fork, threads) will work on a number of different platforms e.g Unix/Windows etc. I'm just learning Ruby and whilst the syntax looks a bit odd it is actually pretty intuitive once you get going.
Perl is very good for string manipulation and is pretty easy to learn the basics of. Ruby looks along the same lines and in conjunction with the Rails framework seems set to take off too from a web-design point of view. I'm looking at this as an alternative view to a Java/Struts combination.
There are big differences between a language like C# and others like Perl/Ruby which make both well worth learning for different reasons.
Personally, I'd find C# would be preferable for writing a Windows app with a GUI (unless you want a go at Perl/Tk) whilst Perl would be better for writing code that runs on Unix or needs to be portable across platforms. The loose typing of Perl/Ruby also lends itself to different programming styles, sometimes making things easier, and other times not.
IMHO it's well worth learning both. Hope that's useful.
Jim