Fill flash can work although you should try and use a gel to balance the light with daylight...

I am partial to reflectors, because then you are using the same light. Even just a small one might have worked for the shot you were taking there.

Also make sure to meter to the right, and as ysap noted use RAW... push the exposure as far to the right as you can and then you can usually recover a good deal of shadow detail using Photoshop or other editing tools.

Fill flash can work although you should try and use a gel to balance the color of the light with daylight...

I am partial to reflectors, because then you are using the same light. Even just a small one might have worked for the shot you were taking there.

Also make sure to meter to the right, and as ysap noted use RAW... push the exposure as far to the right as you can and then you can usually recover a good deal of shadow detail using Photoshop or other editing tools.