There are a number of way using which you can find websites owned by same person. Some of the methods are more relaible while others may have errors. Here I have made a list of method that can be used to find all the sites by the same owner

1- Reverse IP Lookup Method

In this method we look for all the sites hosted hosted on an single ip. Regarding accuracy – It may be that this site is hosted on a shared server and not all the domains are owners by same owner. For complete details on how to do a reverse ip lookup see this article

2- Google Adsense Method

In this method a search is done for all the sites that use the same publisher ID for adsense, and since its understood that the a single user has only  one adsense id we can track all the websites owned by him. But not all websites use adsense so sometimes this method my not be of use. For complete details see Find Sites using same adsense account – SOLUTION

3- Google Analytics Method

This method is same as the above method but only that it uses analytics code. See a detailed step by step tutorial here

4-Same WHOIS Detecting method – DomainsTools.com (Paid Method)

You need to purchase an account on domaintools.com (can use trial 10 days period) and see the domains registered by the same person, (It used the WHOIS.  For more info see Domaintools.com WHOIS history REVIEW )

tags: methods to find sites owned by same person, owner of list of sites