This is not especially difficult to do, considering that jetpack airspeed records don't really exist yet, but when you only have 30 or 40 seconds of fuel, you have to make sure and remember to leave yourself enough time to slow down.
The actual jetpacking starts at around 1:30, but whoever edited the video did a pretty shitty job and loves slow motion too much. Still, dude gets up to 61MPH. Which is impressive considering he's towing like 30lb balls.
Jet Pack Speed Record [ohgizmo]