As we all know, Google Caffeine is launching on a single data center until after the holidays so that online retailers don't get a nasty present from Google.
As I promised then, I would let you know what data center the results went or go live on, when I hear. There are some discussions and chatter at WebmasterWorld that one data center may have Caffeine results. Google has not confirmed it, nor do all webmasters believe these are Caffeine like results.
The data center is 216.239.59.103 and you should give it a try yourself. Matt said that even if they do give out an IP address, it is possible that non-Caffeine results will show on that data center for some people. So maybe this is Caffeine and some don't see it? I am not sure - I am pretty sure Matt can confirm this IP as the data center or not - after he gets back from Las Vegas.
Forum discussion at WebmasterWorld.
Update #1: Some are saying this data center has moved to 66.102.7.18.
Update #2: Google's Matt Cutts replied to me on Twitter saying, "@rustybrick I don't think that IP points to Caffeine."

Comments:
manu
11/16/2009 03:39 pm
it looks like caffeine! thanks.
Beany
11/16/2009 04:04 pm
Over here at the Netherlands, these arent caffeine results. They are 100% the same for the current google SERP.
Majed
11/16/2009 04:42 pm
Have to disagree with you guys :) Here is the IP Address for Google Caffeine: http://66.102.7.18/ Check it out, and simply enjoy it.
jan
11/17/2009 01:06 am
I checked both with my local server. They are all three identical for the term Myrtle Beach real estate. I don't think either one is Caffeine.
Vineet
11/17/2009 05:18 am
same result for me
max
11/17/2009 04:51 pm
66.102... gives me the old caffeine result for the three keywords where the sandbox differed from google.com, so I think it's worth investigating. Thanks for the report!
Justin
11/19/2009 05:07 pm
it seems Beany is right, i see Caffeine results on 66.102.7.18 too. Thanks :)
Todd
11/21/2009 02:16 am
Google Caffeine has been showing here on and off for 2 days. ( you may have to hit reload a couple times) http://209.85.225.103/search?hl=en&q...earch&aq=f&oq=
Todd
11/21/2009 02:19 am
I will try that again with the full url. http://209.85.225.103/search?hl=en&q=widget&btnG=Search&aq=f&oq=
No Name
11/27/2009 10:15 am
Any updates ?
cubahotels
12/09/2009 11:54 pm
It seems caffeine is running at 64.233.169.104 and other 64.233.169.XX ip block machines.