I'm looking to get into application development, such as Facebook or Android apps and games. I am doing this for fun and to learn. Once my skills are to par I would like to have some side income from the apps, but I'm not banking on living off that (just so you know where I'm coming from and know what my end goals are). Currently I know and am familiar with PHP and frameworks such as cakephp and yii. However, I have been wanting to learn another language to broaden my horizons and to become a better developer.
So I have narrowed it down to 2 languages. Python, and Java (I can already hear people cringing at the difference in the languages I have chosen, but I have some reasons).
Python: closer to PHP that Java. Cross platformability. Also great as a general scripting language and has many file system level benefits that PHP does not. Cleaner syntax, readability, blah blah and the list goed on. Python will work great for cross platform apps and can be run on many OS's and is supported by Facebook for app development. But there is no support on Android (for full fledged apps).
Java: a much stronger typed language, very robust community and corporate backing. Knowing Java is also good for personal marketability for enterprises, if you're into that. The main benefit here is that Java can write apps natively for Android and the apps can be ported for web versions to play on Facebook. So while I have seen many developers prefer Java over the two, Java has this significant advantage, where I can market my apps in both markets and in the future build more potential income. But like I said it is for fun. While money isn't the goal, it would still be nice.
PHP: I'm putting this here because I know it already, and I'm sure a case could be made for it. It obviously works great for Facebook but like Python does not do so well on android.
While it's mostly the realm of 'application development' that appeals to me, I do find Android apps fairly interesting and something that has a ton of potential to. But then again Facebook has a ton more users and the apps can also potentially be more immersive (desktop vs. mobile). So this is why I'm kinda stuck on what route to choose. Python for Facebook and web apps, with likely faster development to production times, or Java which can be developed for any of the platforms to make apps.
Side note: I'm not really trying to get into 3D development, mostly 2D. And I also want to make an app with real-time play (websockets, etc). Someone mentioned node, js to me for that but Python seems to be more globally versatile for my goals.
So, to anyone that does Facebook or Android development in either language: what do you suggest? Any input is valuable and I do appreciate it. And sorry for being long winded.
EDIT: as mentioned in one of the answers, my primary goal is gaming. Although I do have some plans for non gaming apps such as general web based and desktop based ones. But gaming is my main goal with the possibility of income.
EDIT: Another consideration could be Jython. Writing Python code which is converted into Java bytecode. This would allow the ability to do Android apps using Python. I could be wrong though, I'm still looking into it.
Update 1-26-11: I recently acquired a new job which required I learn .NET using C#. Im sure some of you are cringing already but I really like the whole system and how it all works together between desktop and web development. But, as I am still interested in Python very much, and after some research I have decided I will learn Python as well as the IronPython implementation for .NET. But (again: I know...) since .NET is mostly a Windows thing and not as cross-compatible as I like, I will be learning Mono which is a cross platform implementation of .NET where I can use what I learn at work using C# and what I want to learn, Python/IronPython. So while learning and writing C#/.NET @ work I will be learning Python -> Mono -> Iron Python for what I want to do personally. And the benefit of them all being very closely related will help me out a lot, I think. What do you guys think? I almost feel like that should be another question, but there's not much of a question. Either way, you guys gave very helpful input.