Have you ever felt the need to lookup cell phone numbers? Maybe you get threatening calls or you suspect your partner is having an affair? Whatever your reason is, there are ways to do a lookup on cell phone numbers for free.

1. Use your favorite search engine - mine happens to be Google - and type in the phone number into the searchbox. If you are lucky, the phone owner's name pops up in the search results. If, however, this first step didn't produce the results you were hoping for, do another search but use quotation marks this time, e.g. "555-5555-1234".

Using quotation marks instructs the search engine to only look for websites on which the phrase - or in our case the number - appears exactly in this order. This way your chances to find the owner of the cell phone number increases.

2. If you weren't able to find the cell phone number on any website, there is another possible way to look it up. More and more people are using social network sites these days (e.g. Myspace.) Many of these people publish their private information - including their cell phone numbers - on these sites, without being aware that you can actually do a lookup on them.

You might have to sign up for an account on these sites, but it is easy and free. To increase your chances to find the cell phone number you are looking for, you should do a search on the three most popular sites (Myspace, Facebook, and Bebo.) Just enter the cell phone number you want to lookup into the search box.

3. If the second method didn't produce any results either, you might want to use a cell phone lookup service. These services have a very small fee, but they have millions of cell phone numbers in their database, and you only have to pay if they actually have the number you are looking for in their database. They have up-to-date data, and their results not only include the cell phone owner's name and full address, but for example also any household members, satellite maps, and the owner's address history.