I’ve got a creative thinking mentor. It’s not UX mentoring, but we cover a bunch of things that can be considered UX-related (such as communication, technology, how the brain works and storytelling) as well as things that aren’t very UX-related at all (like language, maths and politics).
We used to mainly communicate via handwritten letter (I keep meaning to go back to that) or by phone, but these days it’s via email every week or two.
I find him invaluable for inspiration, focussing on what I find important and developing my critical thinking. He’s quite a lot older and is great at bringing both innovative and forgotten things to my attention, and loves to ask questions that it takes me weeks to work out what he’s ultimately getting at. =)