Q:

Any Stock Trading using Bitcoin? 

I would imagine Bitcoin is the perfect tool for students to learn about economic and learn about investing.  Any out there available yet? 

A:

There are a few currently operating Bitcoin security exchanges with non-negligible volumes:

Cryptostocks
https://cryptostocks.com/
Opened at the end of June 2012.  Run by the owners of Vircurex, a fairly popular alt-currency exchange. 

Bitfunder
https://bitfunder.com/
Launched mid-December 2012.  Run by the owners of Hashpower, a mining intermediary of sorts. 

BTC Trading Corporation (BTC-TC)
https://btct.co/
Currently in beta.  Launched in November 2012 by the owners of Litecoin Global (a Litecoin-based security exchange; not affiliated with or related to Bitcoin Global, the GLBSE parent company).  

MPEx
http://mpex.co/
Opened in August 2011.  By far the largest of these in terms of (claimed) combined asset market cap and trading volume, but not at all newbie-friendly.  Run by Mircea Popescu. 

The Bitcoin stock exchange scene collapsed into utter chaos after GLBSE shutdown unceremoniously.  You'll find many assets listed on multiple exchanges, some assets still being transferred from GLBSE, and some former GLBSE assets currently not actively traded on any exchange. 
Try, learn, and have fun, but caveat emptor (buyer beware).  Read the contracts carefully; make sure you know exactly what you're buying.  Research the asset issuer in detail, particularly their past history, before you purchase.  Don't equate legal identification with trustworthiness.  If you're unsure about anything, ask someone more experienced for their advice - most are glad to help.  Last but not least, never under any circumstances invest more than you can afford to lose.