i just got a new road bike this winter, and (obviously) am still not quite used to riding with clipless pedals. when i first moved to sf, i could not understand why people would ever want to bike here with all of the hills. more than that, i couldn't understand why people got up so early in the morning to do so. now, 18 months later, i am one of those early-rising bikers! i get up on saturday mornings and head to spin class, where i kill myself for an hour and fifteen minutes so that when i actually hit the road early sunday morning i can make it up the hills in marin with relative ease. it's kind of amazing to me that i am one of the bikers now. they still seem so serious to me; i am not yet really one of the pack. but i can keep up with the veterans (and even pass them sometimes), especially when going up hill. i'm not yet used to the speed on the down hill, and while i can pass them on the way up, they woosh past me on the way down. i still have a lot to learn . . . as you can tell from the picture!
UPDATE: thanks to mybloglog, i've noticed that there is a fair amount of traffic that hits this page when people search for clipless pedals. here's the answer for those of you that are curious about how to *not* end up looking like i do, courtesy of Sarah Clatterbuck, Team Velo Girls:
-First, straddle the bike with both feet on the ground.
-Second, clip your stronger leg into its pedal while the other foot is on the ground (stronger foot would be the one you put in back on a skateboard or surfboard - if you've never done either, you will have to guess).
-Third, pull the crank backwards with the foot that is clipped in until you have the pedal almost as high as it can go but a little forward.
-Fourth, push down on the pedal with that leg so the bike gets rolling and lift your butt onto the seat
-Fifth, after you are comfortably and safely seated (and hopefully still rolling), try to clip in your other foot.
If you don't have enough momentum to get clipped in after you put your butt on the seat, you can get off the seat and put your free foot back on the ground and try again. To dismount after you're clipped in, rotate the foot you want to put down until it comes out of the pedal, put the foot that is still clipped in at the bottom of the pedal stroke, lift your butt off the seat, and finally set your free foot down to stop."
My addendum:
also, remember that you can begin pedaling with both feet even if you're not clipped in. so clip in the one foot, start pedaling (as sarah explained), and keep on rotating around and pedaling with both feet (one clipped, one unclipped) until you get your second shoe properly clipped into the top of the pedal. you shouldn't try to clip both feet in standing still, only when you're moving, because you will topple over.