About a year ago I saw a music video using this very cool effect. I've always wanted to play with it and was reminded to do so after watching adam deeves' video on time displacement ( vimeo.com/409951 ).
Instead of using After Effects, I decided to see if it was possible to recreate the slit-scan video effect in Flash using my web cam. The video above is the end result and works even better than I hoped.
I'm going to be putting this online soon so everyone who has a web cam can play with it.
Update: I posted it online caseypugh.com/slitscan