I originally posted this in the SFIV thread but thought it might be better in its own thread. ;)
For those (like my self) who are having trouble with the trail challengers are these videos for all the characters.
http://www.youtube.com/profile?user=kalelulen4&view=videos
further (textual) guides for the challenges:
http://www.eventhubs.com/news/2009/mar/12/street-fighter-4-trials-walkthroughs-complete/