There's this very cool blog I found on the nets.
Antimatter is the ultimate fuel for high-speed space propulsion. While we can in principle make do with nuclear rockets for interstellar colonization, antimatter is in a different league entirely. They would enable interstellar travel at speeds of up to 30 to 70% of light speed, three to eight times higher than any form of nuclear propulsion, even the Orion ship that I love talking about so much.
The problem, of course, is producing antimatter in sufficient quantities. We need tons—literal tons—of antimatter to power a starship of any appreciable size. That is somewhat more than current antimatter stockpiles, which are barely capable of powering a lightbulb. Although antimatter production is increasing exponentially, we need to do better. Much better.
This blog will examine some of the weird and wonderful ways we could get more antimatter. Because antimatter is awesome. And so are rockets. Therefore, antimatter+rockets must be even more awesome, right? Right? Okay...just so as not to scare everyone off with my mad ravings about strange and futuristic things, I'll begin with methods that are mostly just extensions on existing technology, not some absolute craziness.