Here you go:
Maybe this is just with me, I don't have a great audience on Twitter, and I doubt it if anyone else has tried this:

Take the case of Actor Siddharth. His article on enwiki used to say Siddharth Narayan. He tweeted out [Verified account] saying that his name was Siddharth Suryanarayan and not Narayan. User:FilmLover1426 changed the name but when it came to moving the page, she told me, "I need to contact some one to have it changed", inspite of me telling her, she could do it herself. Then, there came an issue of Reliable sources, she argued that the tweets would be sufficient.

Another case, this time more successsful, would be of the Bangalore Helicopter pictures. I found it on Twitter, got in touch with the fellow who uploaded, but got no result. But then, a friend of his, who accompanied him on the ride, had uploaded to FlickR, and thanks to a mail sent by me, AroundTheGlobe and AshLin, he released his images under CC-BY-SA.

I'd concentrate more on socio-economic forums online than Twitter for getting new people to Wikipedia.

Getting Wikipedians to Twitter is easy, the reverse is a bit tough.