One friend sometimes asks me about horse stuff. But that's just because I spend lots of time around someone knowledgable, and have picked up a few things from them.
Usually I just hang around at the outside of conversations and talk if there's something I know and they don't.
Well, also on occasion someone will come to me if I've given them money or something for more help. I'm pretty generous and free with money if I have it on me, and I think there have been a couple times that I've been treated as an ATM for the duration of a trip/camp/other situation where I am carrying money with me and using it for stuff I need.
Jk-joking, that never happens. They come to me for information on media events like the possibly discovered "God particle," which I consider a misnomer, all this God-mongering, but then I have to explain elementary particle physics and what a boson is and how it differs from a fermion, building up an understanding of the Higgs field only to find out they don't give two shits for anything I'm saying, and ask: "But why is it called the God particle? What does it mean????"
... usually they just come to me for advice on life problems or such, because they know I can handle anything they can tell me, I won't be offended by what they've done or what they want help with, and I'll sit and listen and provide insight without telling them what to do or think they're jerks for what they've done. I am pretty soft-spoken and impartial and productive.
I'll usually get asked questions, too, in areas they know I know something about. (So kind of the "sage" thing.) I would also get asked a lot about music, or asked to perform for particular events.
I think though i'd just like to be asked to be part of the group from time to time, when people get together. It helps me feel like I'm connected and not so adrift.
Depends on the person. Sometimes emotional support - they want me to help analyze it logically, I suppose. Some come to me for computer help. Classmates come to me for help when they're stuck on a problem, no matter the subject. I seem to have "Ask me - I can help" plastered on me somewhere.
Second opinions, perspectives on things they think i'm knowledgeable about, and help with problems that require problem-solving on the fly (apparently people really hate doing this? Or did older generations suddenly decide they were incapable of doing it once they passed a certain age? At least that's how it is in my family ....). And my INFP friend sometimes comes to me for emotional support (lulzwut)
People typically come to me for writing advice. They assume that I'm an expert at editing since I'm an English major. I neither get that connection between editing skills and being an English Lit major , nor do I get their impression of me as skilled editor. I'm not that great at writing; I have to edit a post many times before it sounds coherent. Oh well.
...to exploit my vast knowledge in different area of expertise. I was recently asked if I knew some well known pedophiles. I was first applaud by the question and why the person would come to me specifically for answers, but then I just started listing names effortlessly.