If you are just going to learn a programming language, there is still plenty of competition. Instead, I would suggest that you build a web-based product. It involves a lot of moving parts that you will get familiar with. It is quite an arduous task.
Don't focus on the tool (programming language); instead, step back a little bit, see the bigger picture and build something with that tool. People are much more appreciate of such efforts.
Edit: In case you need some hand holding in the initial stages, I am more than willing to help.
Is there a way you can collect browser stats? You should be able to pull something from the server logs. Once you have done that, take a look at them numbers and you will have a fair idea on what your userbase prefers. If I see something like 50% of IE7, I would think that it's a good business decision to support IE7 development if my bread and butter depends on that.
I was able to augment Pimsleur's Japanese tapes with some reading to crack the old Level 4 of Japanese Language Proficiency Test. It was a very good starting point. Worked well for me I would say.
