would be good especially as I would like a trapezoid.

Cheers

oops, read the preceding post I was just editing while you were answering... lol!

For a simple trapezoid, you could probably use Paint in Windows to quickly create it.

The cookie cutter needs major improvements. I would like to use it for dropout removal like a mask. Would like lots more control of shapes.

I have set the size to 1024x576 but when added to the time-line (DV Widescreen) there are black borders each side.

Also, I have the trapezoid as black with the rest white. I am assuming that I would use the Chromakeyer FX on the black. Is there another (better) way?

Cheers

Yu can use the Pan/Crop tool to get rid of these black bars on the sides. there's even a switch I think ("stretch to fill frame" or something like that) that you can turn on and off .
Using the parent/childs tracks will be the simplest way, in my opinion, to key your image through.
Your cookie is on track one, your image on track two and you switch this little arrow on left of the track two (on the border of your screen) to turn on the parent/child composite mode.
Like I said, what is white in your cookie image will let the image from track just under pass through and what is black will block it. You can use the Invert plugin fx to easily invert what's black and what's white.

Terrific, fUtZ, you've been a great help. The first time I have got the parent/child relationship to work and understand it.

One thing, though, drawing the shape in Paint has left me with jagged edges should I have got rid of these in Paint (how) or in V4?

Cheers

Probably easier to correct it in Paint. Just re-do a perfect mask and everything will be easier after in Vegas.
Remember: the more you ask to Vegas, the more time you'll probably end up rendering...

Also make sure you draw your mask at least as large as the frame size in your video project. I could see that if you drew a 160x120 image for the mask and then imported it into a standard size project then Vegas would have to blow the mask up 4x which would definately introduce jaggies.

I created the mask as 1024x576 for DV Widescreen.

...exactly. Paint is very "prone" to jag the lines but if you go with twice the definition you need (in Paint: Image/attributes (or properties?)) you get a decent deal out of these jaggies.
In NTSC (Vegas), that would mean starting with a project 1440x960 pixels in Paint. Be sure to draw your shape "dead-center" since the image will probalby expand "outside" your screen with that definition...ie:scroll before drawing.
And use the "line" tool to draw such a shape; that'll be easier and more accurate than using the free hand pencil (I figure out that's what you did but... just to be sure)

... again, you posted while I was replying!
The definition of your drawing depends on the Properties (from File menu) you defined in Vegas. Check this out then double it up for your drawing.
I shoot in "widescreen" mode on my camera (sony pd-100) but since it's a "fake" 16:9 that just crops the image with two black bars on top and bottom, I use the standard NTSC format in Properties and render the same to keep these black bars in the end when I watch the result on a TV set (that is 4:3 by definition unless you already got one of these widescreen 16:9 TV at home...).