I'm using Final Cut Express HD, and want to know if there is any way to make speed ramps (where an effect eases in or an object moves then slows to a stop...) for like slo-motion. I have footage that I want to suddenly begin to slow down over 10 seconds, easing to the slower speed. Is this possible?

Any help greatly appreciated.

Use key frames.

How do you use key frames to apply a speed change?

I'm fairly sure this isn't a FCP only feature. Go to the motion tab of a clip, and look for the time area. You can adjust the ramp, which defaults to a liner ramp, here.