Say you met someone at a cocktail party, and realized afterwards they might be a very good contact for a job lead. Trouble is, all you remember is their first name. You can sometimes find out a surprising amount of information about someone on the internet, even with just a first name. Sometimes...! Here's how to look.
Detail What You Know
Usually, you'll know a bit more than a person's name when you're doing a people-search for information. For instance, you may know the state or city they live in, or even a street or zip code. Perhaps you have a phone number as well, or know where the person works, or attends school. Whatever snippets of information about the person are available, write them down, so you have them all in one place.
For instance, my neighbors wanted to know the birthday of a new neighbor of ours, who we all knew only by first name. With just the first name -- along with knowing his address and phone number -- I was able to find his birthday date. And in the process, found his surname as well.
If a person's first name is very common (such as my first name, which is David) then your odds of tracking down a lot of information are pretty slim. On the other hand, I know someone with the first name Grietje. Now that's more like it! With an unusual first name to work with, you have a much better chance of finding information.
So, if you're looking for information on David in San Francisco, then you might as well forget about it... you'll find so many possibilities that it will be impossible to sort through them all.
However, if you're looking to find out something about Grietje in Peoria, then your odds are much better, as there is likely to be only one or two people, at most, in a mid-sized town with that particular first name. The more unusual and rare the first name, the easier the search.
Give Google a Go
Using the (hopefully unusual) first name, along with any other facts you have, such as a place of work, type your information into Google and see what pops up. Truth be told, it's very unlikely you'll find anything this way, but a Google search is such an easy thing, that you might as well give it a shot.
Use Specialty People-Search Tools
Most telephone book sites and directory sites will NOT let you search for a person on just the first name. A last name is required. However, there are occasional sites that will let you search on just a first name basis. These are the sites you need to find, and use for your first-name-only searching.
A good national search tool is Intelius, where you can search with just a first name as long as you enter a state (or other location) as well. Reference USA also allows first-name searching, and is available at many public libraries.
Also explore searches particular to your person. For instance, if you know what college they attend, there may well be an online student directory at the school' s website. If so, see if it allows first-name-only searching. Give social networking sites like Facebook, MySpace, and LinkedIn, a try as well.