going down a hill on road bike

[Shut Up Legs]

Go down with your feet off the pedals splayed out in front of you shouting " WHEEEEEEEE!".

Yes, if nothing else, it will make motorists notice you more, and that's always a good thing.

Also, @jamma, a tip from this page may help you:
http://cyclingtips.com/2011/03/speed-wobble-when-the-bike-shakes-its-head/
Look for the bit "3. Incorrect weight distribution", and read the section, it contains useful tips on descending more safely.

 

[Gert Lush]

My fastest decent was 31mph! It was great! I was almost blind because of the tears streaming from my eyes, the road wasn't the best but I had the time of my life

 

[HLaB]

Lots of times I've been overtaken by cars at the start of a descent, then held up by them as they crawl down. They never pull over and let me past.

Agreed ^^^^^^ although I have had the occasional muppet pull out in front of me and sheepishly throw on their brakes and I have to go by,whether they allowed me though :-/