Are there any good tools to analyze the clickstream of individual users in Apache web server logs? For example, I'd like to be able to click on a visitors IP address and see all pages the user requested.
Two of the best opensource web analytics are OWA and Piwik
OWA is supporting click-stream and the demo is here : http://demo.openwebanalytics.com/owa
Piwik is offering a clickheat plugin
demo : http://demo.piwik.org/
The best tool that i have used is Splunk(http://www.splunk.com/download/) It's not cheap, but real cool and give best speed and functionality that you ever need. Also they have freeware license for aggregation 500mb of data per day. I used this licence on my production game servers(about 3m users) and haven't any problem with this limit
I found the Follow-Me plugin for AWStats. Unfortunately, it is quite buggy, i.e. it only works with IP adresses, and not with hostnames. Furthermore, it does only show clicks from the last day, i.e. it doesn't work for older logs.
What means that some users won't be tracked, but that there's more information to gather.
If you have the option of actually installing a tracker code on your website, you should consider doing that instead.
If you want to do this, you should take a look at google analytics, which can give you extremely specific details about pretty much anything. Also the thing you want, even clickstream (which they call visitor flow). Heres a pretty great example, that shows it pretty good.
You could also use some form of analyzer that you have to install on your server, but this feels like a hassle, and often its a huge annoyance, because you cant customize it like you want.
Analytics has a pretty steep learning curve, but i use it on a daily basis to analyze the flow of my visitors.
If you have the resources to pay a little for your statistics, you might want to take a look at CrazyEgg, as they offer some pretty advanced statistics, including clickstream, but if it is per ip, i cannot tell, i have never actually used it before, but have been recommended it.