If you want to have some fun try this application.(login needed as demo/demo)
There are 12 questions, I missed one, maybe soon there can be an Apex certification?
Questions Answered: 12 Correct: 11 Pass
Minimum Required Percent: 60% Percent Correct: 91.7%
Unanswered: 0 Incorrect: 1
Allocated Time in seconds 600 Elapsed Time in seconds 185
Test: APEX General Knowledge Grade: A-
Apex is the most relaxing development tool I used and still use, without any competition, daily I search for new needs&wants just to have the opportunity to develop database centric web based applications with apex in my organization, this is like a virus, each time as I get more experienced with Apex the customers are happier with the results and new requests flow :)
Apex is free, Apex is easy to learn, Apex comes as a part of the 10gR2 XE and 11gR1 SE&EE, if you are a database developer or administrator and looking for an extreme love try Apex!
ps: if you need more fun check this one also :)