A fraud alert can be a very effective way of preventing ID thieves from opening accounts using your identity without prevent you from opening accounts when you want. A fraud alert is basically a notice that appears on your credit report that alerts potential creditors that you may have been a victim of ID theft. The notice will also include your contact phone number so that a potential creditor will contact you at that number before they issue credit.
Fraud alerts will remain on you credit report for 1 year so you do need to remember to add another alert when it falls off. In some cases, you may qualify for an extended fraud alert which generally requires a police report or other corroborating evidence of ID theft.
In order for a fraud alert to be effective, you do need the alert on all three of the major credit bureaus. The good news is that if you do add a fraud alert with one bureau, that bureau will communicate that fraud alert to the other 2 credit bureaus.
You can set a fraud alert by calling the bureaus but they also have websites set up so that you don't have to wait on hold to speak to an agent. Here are the websites that each of the bureaus have set up for administrating fraud alerts: