doing a manual to get over obstacles
Joe Lawwill shows how to do a manual (as opposed to a wheelie) here at about :43 into the video:
http://www.youtube.com/watch?v=CdNKq...layer_embedded
To practice this, stand next to your bike with your hips touching the handlebar. Now thrust the bike forward in one quick movement. Don't move your feet. Push out, don't pull up.
He suggests you thrust your bike forward, like you're throwing a punch. Do it with commitment. At the end of the bike thrust, the front tire will lift off the ground without you pulling it up with your arms. Ears should hit your shoulder when you are crouched behind the saddle. So think of it as you are throwing a punch while moving your butt over the wheel.
This technique doesn't require pedal input. :)
For an illustration of this, refer to pages 62-66 of Mountain Bike Action, May issue.
More instruction videos here:
http://www.bikeskills.com/blog/?page_id=422