Presently I'm using two different Camera's...

The Sony PD170 (SD) and the Canon HV20 (HD).

To allow mixing the two formats on the same time line I'm experimenting
with two software programs, Instant HD and Genuine Fractals, to uprez
the SD footage to HD.

During my testing of the uprezing of SD I'm finding that the SD material has more noise than the HD footage coming from the HV20....

More testing to match the noise levels took me to another program called
Neat Video...

It is doing wonders on the uprezed SD footage and I've just started to play with the footage from the HV20 using the program too......

Its a " WOW " conclusion when applying the noise reduction program on the
HV20 footage..... and as we know there's not much noise that needs removing....

But I thought I'd mention this option for those times when you had to shoot in not the greatest light conditions and your footage comes out a bit noisy..

There is a solution that works very well with the HV20 footage....

I should say, I have no connection with these folks at all.... just found this
product last night and its proving to be a good resource for better footage
from the HV20..

http://www.neatvideo.com/examples.html

For Mac users, another option:

http://www.revisionfx.com/products/denoise/

Those previews on the site are absolutely incredible. Has anyone here used it? If someone buys the DE:Noise plugin, please use it and post an example! I'm dowloading the demo version now.