Except for mining (which is getting more and more specialized and risky) and investing on GLBSE are there other ways of earning btc? And I'm not talking about trading on silk road, only online stuff 
You can do in-person trading.
- http://www.LocalBitcoins.com
You set the price. Have the person meet you.
This is because even going to 7-11 and picking up the red phone is too much work / too complicated / too risky / etc. and meeting up with the seller and doing a trade face-to-face is worth it to some newbies, and they are willing to pay a little extra.
+1
Helps if your in a heavy populated city. The closer people are to you the better.