I'm going to be creating some flash files tomorrow.
What are the best exporting settings? Each file will be 3 minutes in length so obviously I'd like them to playback online with as little loading time as possible.
Normally I just select 'web small', but there must be more I can do?
Do do you need compatibility with previous versions of the Flash plug-in? If so, exporting FLV with the "web small" is a good starting point.You could get a bit better by using 2 pass encoding, but in order to do that, you'd have to render an intermediate Quicktime or AVI file and launch Adobe Media Encoder in standalone mode (it's in the applications folder).
If you can get your viewers to use the Flash 10 plug-in (9.0 r115 and higher, actually), you can use the H264 format (or F4V, same thing wrapped in a Flash video file). SInce it uses more modern/efficient encoding, you can get the same quality and reduce the bitrate, or better quality with the same bitrate. The "F4V - Web small" preset targets the same data rate as the FLV preset you've been using. You can lower the bitrate to from 0.4 Mbps to 0.35 and it should be fine.