I purchased this HDMI-VGA adapter to be used with my ATI 5770 so that I could do Eyefinity. I used it with several different 19" 4:3 aspect LCD screens and found that the resolution could not go higher than 800x600. If I tried to set the resolution higher, it would scramble the video on the display like a cable channel you didn't subscribe to (you'd need to have lived in the analog age).
Using it with my Gateway NV44 laptop, however, was completely successful in producing higher resolutions on the exact same 19" LCDs and on widescreen LCDs as well.
The adapter detects as an actual display and not an adapter, so the display that is connected behind it is not necessarily detected properly. Because of this you do not have very much control over the refresh frequency.
I would recommend this adapter if you need to output from any laptop using HDMI to a VGA connection.