Here’s a sweet little slow mo bike film that has used Twixtor to slow the video down to 10% or less. Everything was shot on the Canon 7D in 720p 60fps. Twixtor has had some mixed reviews but this little video is smooth..
Twixtor is essentially a plugin for After Effects, Final Cut, Premiere etc that enables you to speed up, slow down or frame rate convert your image sequences. Twixtor then synthesizes new frames by warping and interpolating frames of the original sequence. As demonstrated by the film above it seems to work best when the background is kept as simple as possible. It also seems that shooting with the shutter speed as fast as possible gives a smoother effect.
Think I may have to experiment with Twixtor over the next month or so.