1. Respond: If you feel safe enough to do so, assertively respond to the harassers calmly, firmly, and without insults or personal attacks to let them know that their actions are unwelcome, unacceptable, and wrong. Here is advice from Martha Langelan on dealing with drive-by harassers.
2. Hand the Harasser a Flier: If speaking feels too scary, you can also hand the harasser information about harassment. Here are some examples from Appetite for Equal Rights, Street Harassment Project, graduate student Sarah VanDenbergh, and Stop Street Harassment (Not Hey Baby, Show Respect 1 | 2, Wait a Minute 1 | 2, Picking up Women 1 | 2).
3. Step In: Intervene when someone else is being harassed to help them out of the situation and let the harasser know that their actions are not condoned by others. Men engaging in this tactic can be particularly powerful since men (majority of street harassers) look to other men for approval. Check out this great bystander campaign from the University of New Hampshire.
4. Report to Employer: If the harassers work for an identifiable company, call or write the company to let them know that their employees are harassing people on the job and why that is unacceptable. (Here are three examples submitted to this blog about how women successfully did this. Even threatening to report harassers to their company can make a difference.)
5. Report to Police or Transit Workers: Take actions that will create real consequences for the harasser, such as reporting the person to a police officer or other person of authority, like a bus driver or subway employee. [Here is a statute in New York against serial acts of public lewdness and in Independence, MO, it's illegal for drivers to harass pedestrians or cyclists]
6. Report with your Phone: If you have a smart phone and are in the U.S., download the HollaBack phone app and report your street harasser and if you are in Egypt, use HarassMap to report harassers via SMS texting.