The main engines used on Galaxy class spaceships, like the USS Enterprise, on Star Trek.
The warp engines use some sort of matter/antimatter reaction to propel
the ship through the galaxy at amazing speeds.
There are certain "levels" of warp. 0 being the slowest, 10 being theoretically the fastest. Nobody knows exactly what happens when the warp 10 boundary is crossed. If I recall correctly, there was a theory about inter-dimensional travel though.
Update: See below. General Wesc is obviously more of a trekkie than I am.
c (the speed of light) is 670,000,000 mph.
Old warp scale
- c*1
- c*8
- c*27
- c*64
- c*125
- c*216
- c*343
- c*512
- c*729
- c*1000
- c*1331
- c*1728
- c*2197
- c*2744