How do I get pixel measurements on a layout prototype easily?

I use Scribus for that sort of stuff. It allows me to choose the default units (px, pt, in, etc) for each drawing (in Page ->Manage Page Properties and also in File -> Document Setup). Do you have a setting like that somewhere? If so, you could switch to pixels, create a layer for your “ruler” and draw the ruler in, then go back to whatever units you’re working in and just do your design using other layers, without messing up your ruler line. Does that help? Did I understand your need correctly? Sorry, but I know nothing about Fireworks.

Good luck! :)

See if you can use guides.

If your developer is worth a grain of salt, there is no need to trouble yourself doing that. Ask the developer if they are used to slicing and dicing images for conversion to Web format. If they are, then they have several options to get images and open spaces sized correctly. Also, based on how they intend to actually slice the layout, they may not want to break it where you think they will.

When I am doing it working from a customer supplied graphic, I use guides. I can pull them into exact alignment with any element in the image. I do this with the image magnified 500 or even 1000% so they are exactly on the junction I am looking for. Then in my graphics program, I right click the handle for the guide. I get an exact readout in pixels from the left or top side of the image.

If you have fireworks do you have Photoshop. You can simply specify a total screensize in pixels and all the rest will follow, don’t need dimension bars

If you’ve got a Mac, I highly recommend xScope. It’s a beautiful piece of software with a lot of useful measuring tools—I keep it open all the time. It’s true that you should be able to ask a designer or measure in a graphics program, but sometimes it’s faster just to just pull out xScope’s ruler or dimensions tool.