As someone who helps pre-screen technical résumés, selects candidate lists, and conducts technical onsite interviews of potential software developers, I say
Yes, proficiency at finding online information is a skill that I seek.
Being effective at finding accurate information online goes directly to a candidates projected productivity. Whenever I interview any candidate, there is always a specific portion of the interview devoted to finding arbitrary information online (à la www.agoogleaday.com) By watching you interact with a web browser while performing a search task, I am given insight into your reading comprehension, understanding of logical structures, analytical mindset, and proficiency with web browsers which are part of our development tool chain.
The way that I do this is I pose search puzzles during interviews, usually with a layer or two of indirection from the thing they are supposed to find and center embedded phrases to test their ability to decompose complex logical structures into clean and consistent lines of thought. I then observe their process. If StackExchange is the site they wish to use for accomplishing the tasks I set them out to complete, then I would observe them using se;otherwise, I would not.
I have never seen this listed as a skill phrased as tersely as
"I can use Google" or
"I am a member of StackOverflow" (and I would advise against doing so) but seeing something to the effect of
proficiency with finding complex online information
in your personal qualities, skills, or work experience section is something that I feel is perfectly acceptable. Seeing it reinforced with some certification or continuing education helps me try to know you from Adam.
If you're trying to craft a way to tactfully draw desired attention to your "proficiency finding online information" I would suggest finding the time to take Google's free online courses in Power Searching and Advanced Power Searching and listing them in a [Continuing Education] section after you identify your alma mater. I don't think those particular courses would be too terribly helpful to you as a developer already proficient at finding things, but it gives you something to list on your résumé that is more than just your word.
Identifying that you are proficient at finding useful information is one of several ways to differentiate one's self as a candidate that can be provided a seed of an idea without a thorough explanation and run with it, which our team values. I would suggest to anyone that it is not harmful to say something to the effect of "I am resourceful enough to find the things that I need to complete my job." It goes directly to adaptability.
Considering all other comparisons to be equal, if I theoretically were to have two candidates vying for a single on-site interview, I would favor the one that allocated the limited space of a résumé to identify that they are good at finding things. I don't disagree with you that listing "Google" among one's skills is likely a clunky way to profess this skill, but I feel that "problem analysis & solution discovery" is a very appropriate skill to list...especially on a technical team. There are hundreds of technical documents published by the IEEE, the IETF, the ISO, ANSI, the W3C, etc that contain reams and reams of information. I don't expect anyone to be able to simply recall the information in industry standards by RFC and section, but I expect them to be able to find it if necessary and use it to springboard their thoughts.
We also deal with business problems that don't result in stock solutions. There will be research; there will be consumption of hundred page industry specifications, and cross references between google group threads with stack overflow exchanges with editor blog posts with the official RFCs.
Finding the piece of info that leads you to your next point of research is arguably the most valuable skill a developer can possess. If you have that, you can sling code, and you don't smell bad; you're gold to me.