- look at it again, keep looking at it, still looking at it, ...
- get mad about their pc
- start crying in front of their pc
- kill themself without their pc
- go for a walk and come back with a "fresh" head and have another look
- use Firefox and Firebug to track things down
- write down what's happening and is going wrong, you would be surprised to see you didn't see the "obvious"
- start talking about it to yourself or to another
- ask somebody else to have a quick glance at your code
- post a thread in the forum
- debug, trace, ...
We don't have that much time, as we all have tight deadlines, but some of the above points will help you to find the solution faster. And learn from it, put it into best practices so you don't make that mistake again.
YOU CAN DO IT! IT'S JUST A MATTER OF TIME! AND IT'S FUN!