I read about that a while back how you could go into the future by using a black hole for speed, I forget the exact years but it was pretty insane - Something like a years travel and when you came back to earth it would be 100 years in the future. I would do that! without thinking twice Guaranteed no Nancy Pelosi around when you came back....Unless she cloned herself then I would be like Charlton Heston at the end of Planet of the apes “You Maniacs! You cloned her! Ah, damn you! God damn you all to hell!”
If you could survive a very close pass with a black hole you could certainly achieve speeds that would produce a noticeable relativistic effect.
Hypervelocity stars seem to be the product of a double boost from a lost companion stars and a supermassive black hole. Serious speeds like 1500 miles per second.
http://en.wikipedia.org/wiki/Hypervelocity_star#Hypervelocity_stars
No way to go 100 years into the future with a year of travel. All the relativity BS claiming time has no value and can speed up or slow down is tragically mistaken, at least in pop culture. A unit of time is a unit of time is a unit of time. The only reasonable thing to say is that we lack the ability to conveniently measure a second the way we can a meter. But that doesn’t mean that you can press a magic button, or go faster than the speed of light, and presto* arrive as you in a society 100 years hence.
Sci fi combined with weed has deeply damaged science. Everyone forgets the “Fi” part.