I wouldn't suggest doing a trailer, even the brief 25 second one for Twilight was a pain.
My main issues were with compressing the original file done within Shockwave flash. (an 800x600 file which in total was 80megabytes)
The .avi version on the site, 15 megabytes is only 320x240 resolution.
The .wma, and .smk versions are much smaller (500k, and 3.58 megs respectively) but at the cost of a much lessened visual and audio quality.
Black Water Op's trailer has better luck with it's compression, but in my opinion the amount of true content within it was not worth the effort of making it.
This opinion also holds true to the Twilight trailer, which for me was simply a test to see if I could do a movie in flash, it worked out well so I released it, albiet with problems at first when the original file was a 60meg download.

Unless you are going to do a charcoal-style animation with renders, ship interiors, and characters to tell a story and to be a "cutscene" of quality, don't bother with a trailer... (oops I've revealed too much of future plans... doh!

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AceStaff member FreeSpace Watch
http://freespace.volitionwatch.com/