1. go to the "I am about to fall" thread here
www.guardyoureyes.org/forum/index.php?topic=763.msg75441#new it is a place to call for help.
2. don't think about it, gently move your mind to something else that you find engaging. If you come back to it gently move your mind back.
Don't worry about it don't get stresed about it, just thinka bout something else.
3. Take a cold shower, go for a jog, hang out with a friend, go to bais medresh.
4. If you still feel a strong urge tell yourself to wait 15 minutes and then you can do what you want. While waiting do something else.
5. Also, I recently saw a thought from Rav Yisroel Elya Weintraub ZTL. Right after we we do a mitzva it is an עת רצון for tefilla. For this reason we say a מי שברך after someone is called to the Torah. He has just finished the mitzva of reading the Torah so he can daven and Hashem will listen. This is also why we say הרחמן after "benchin". we have just fullfilled the mitzva of ברכת המזון and we can now daven to Hashem for help in our lives.
If we see a woman who excites us we should remember that if we don't look then we will have preformed a mitzva and it will be an ais ratzon to do daven, and it is more likely we will get what we want. So we should tell ourselves that if we don't look then we will have a specail merit and we will be able to ask Hashem for something we need. Don't look and then daven a short prayer in English. I have tried this and found it to be very helpfull.