Depends... do you pay the electric bill yourself? If so, then sadly the answer is probably that you are paying more to run the PCs than you are generating in bitcoin. BUT, if you were going to run those PCs anyways, then really you are making out better by producing _some_ bitcoin in the process. OR, if someone else is footing the bill, then mine away my friend - PURE PROFIT! 
You don't need to convert your bitcoins to PayPal, etc - just find some local merchants that accept bitcoin as payment. If there are some local "mom & pop" type shops near you that you shop at, you should talk to them about bitcoin. If they don't accept it yet, maybe after learning about it from you, they will decide to. This is very much a grassroots movement at this stage - spread the word!
Jon
You don't need to convert your bitcoins to PayPal, etc - just find some local merchants that accept bitcoin as payment. If there are some local "mom & pop" type shops near you that you shop at, you should talk to them about bitcoin. If they don't accept it yet, maybe after learning about it from you, they will decide to. This is very much a grassroots movement at this stage - spread the word!
Jon