IP address locators are a competitive intelligence tool of some value, although they usually satisfy curiosity more than provide real insight. IP address locators attempt to provide a physical location to match an IP address or website name. The results can be misleading (while still accurate) because the IP address may not belong to whom you think it belongs. For example, using this IP tracker, nike.com is traced to Sunnyvale, California. In fact, Nike's headquarters (where you might "expect" its website to be located) are near Portland, Oregon. It seems likely that EDS, to whom the IP address is really being traced, is the hosting company for Nike's website.
It can still be useful competitive intelligence to know that EDS hosts Nike's website, and if the latitude/longitude are accurate, to know where the datacentre is.
Results can also be confusing for advanced datacentre/host setups: the location of Google websites are notoriously difficult to pin down. Setups such as virtual IPs and content distribution networks further confuse the data.
A caveat: the results that IP address tracking returns can vary depending on the tool used, so it is best to use multiple online tools, understand the different methodologies used, and then pick the appropriate result. Such triangulation should be a normal part of competitive intelligence anyway.
A less commonly used source of competitive intelligence is IP neighbour lookup: who else is hosted on the same host as the target website. For example, while nike.com is hosted on its own server, tiffanys.com shares hosting with a range of other companies. Aston Martin has a number of other domains on its web host that give some hints as to what the company wants to do online.
A recent realCompetitive Intelligence-life example follows. Several retail outlets for sale in London are advertised by jllprop.com, but this website has not been set up and it is not clear to whom it belongs. IP searches show that the estate agent is Jones Lang LaSalle.