[m463]

If you could figure out production and storage of antimatter, space travel would be very different.

I remember reading a Robert L Forward book where he described all this in great detail.

EDIT: I think the book was "Indistinguishable from Magic" which was interesting science-wise but not compelling as a science fiction book.

He also seems to have written about antimatter directly: "Mirror Matter: Pioneering Antimatter Physics"

[ClumsyPilot]

You can start by getting nuclear rockets to work

And imattwr is at the end of a tech tree that we have not started