FlashField is a new module that brings flash node functionality to CCK, allowing flash content to be easily added to new content types.
Note - if you just want to add content (swf, flv, mp3) to your site without the ability to set flashvars, heights and widths then you DO NOT need FlashField. Simply install SWF Tools and use the SWF Tools formatters to format a FileField.
FlashField is designed for those cases where you need finer control over how your flash content is presented. Perhaps think of it as "SWF Tools Formatters+"
Update (April 27, 2009)
Now FileField has an official release I've restarted work on FlashField after a bit of a break. The new work is in HEAD and will achieve the aim of "seamless" integration (I am actually using ImageField as a code template to quickly understand how to integrate the modules). At the moment the 6.x-0.0 code, which required a separate FileField and FlashField won't be developed further as it will be fully replaced by the new model. I will also need to investigate the practicalities of a migration script.
The code is in the very early stages of development and is not yet ready for use. Primarily because it will rely on SWF Tools as its flash handler, and SWF Tools needs to be modified too to enable full support.
The module is dependent on CCK (6.x-2.x) and FileField (6.x-3.x). It will also depend on SWF Tools. This means you can upload mp3 and flv video files and they will play in the configured media player, just like flash node does.
The 6.x-0.0 release of FileField was not fully integrated with FlashField. Therefore to create a content type you added a FileField first, then you added a FlashField.
This changes in the new code - now the FlashField is a widget for handling files, in place of the regular file upload. This is how ImageField works.
Please post your bug reports, feature requests and thoughts in the issue queue.
PS - At this time I'm not making any promises about when FlashField will be "production ready"!
There was a 6.x-0.0 release available. Note the 0.0. This was an early release and was intended to provided a fixed, working reference point to at least make it easy for potential future users to download and try the module. This version required you to make a FileField first, and then add a FlashField. You tell FlashField which FileField it should render using a drop down on its settings page.
HEAD is now tracking development that more tightly integrates FlashField with FileField. The aim is to make it that you just add a FlashField and you get the necessary file upload field built in. This is quite a big next step, and I'm not sure how long it will take me to do. The code on HEAD may also not work at any given time! And present it is "workable" and while SWF Tools will render the content it will not respect any of the properties that are set in FlashField. This requires a fix in SWF Tools that will be made in parallel with development of the new FlashField.