I think being "On Call" for certain hours is a little problematic ...
Firstly customers may be in (very) different timezones, and perhaps neither of us fancys talking about vector calculus at 3 AM 
Secondly there probably won't be many interested people (at first) and so I would have to wait for many hours just to get one job.
And thirdly, I may need some time to actually come up with a solution, depending on the difficulty of the task 

But I could imagine creating an E-mail-adress, where people can send their problems (for instance as a short text or a document), I look into them, and if I have a solution, I reply to the mail. Of course a real-time-chat would also be interesting, but I don't think that you would need video, so I'd be willing to do a live-text-chat for people who need some broader explaination of a certain topic.

In both cases I'm not entirely sure how to handle the price and BTC-transfer ... I totally understand that people don't want to pay a stranger for a solution, they didn't see yet, but it's also depressing to work on something, present the solution and not be paid afterwards 
So probably I would charge some money beforehand and if the customer is happy with my work, he can pay a bonus.

Let's give it a try:
All readers are welcome to PM me problems, and the first 2 of them get a free answer (if I have one of course). I'm very curious, what's going to happen ^^

Thanks for the quick answer, but as I see it, they do not offer a service similar to the one, described in my post. This site tries to promote the use of bitcoin and related software, but (as I see it) no consulting concerning hard math homework ^^

Hey everyone,
I only recently found out about bitcoin and as I think, that it's an intriguing idea, I wondered, how I could earn some BTC. What do you think of the idea, to start an online consulting-service? I study math and physics at an university, and I think many students have to deal with problems concerning math or science from time to time. Many of them could be solved quite easily with my knowledge background.

Would you pay for such a service? Or do you even have specific problems at the moment, which you would like to get solved?

I would be very glad for your opinions on the subject.

Best Regards