It's always interesting when conceptual questions come up that wouldn't have been conceived of a few years ago.
"I do music for television and film. A company in another state wants to do business with me but they've got concerns about how we'd communicate video and audio quickly. What's the best solution for configuring a computer system that will send video and audio over the net? (One where they can send me the video file and I can return them that file married to the music the same day.)"
Based on the wording of your question, it looks like you already have a system that is capable of doing the required production work once you have the files. That's the hardest step. The choices and configurations for moving files back and forth are more limited, though growing all the time. The best solution for you will, to some extent, depend on what you already have and your (or your client's) preferred method of working (file types, formats, etc). To really cover this subject properly would require more space than is available in inSync, but here are a couple of ideas.
Realistically, both the client and you have to be on fast Internet connections - cable or DSL at the least. The faster the better, given that just audio can run about 10MB for each minute of stereo 16/44.1 - and video is anybody's guess depending upon how much it's compressed. Even 30 seconds of video at hi resolution (TV and film will be justifiably so) can be huge, although there are ways to get it done even if Internet bandwidth isn't manageable on one end or the other.
The client can send you a lower resolution clip with a much smaller file size [QuickTime movie, .mpeg or .AVI - whatever your chosen favorite is for work purposes] that is the same with respect to timing as the hi-rez file that they'll end up using (same frame rate/length). You can then produce music to the lo-rez video that will sync to their hi-rez original, and ultimately only have to send back audio, which makes the overall size of files to transfer much smaller, and quicker to up/download. Although this file isn't truly "married" because the final synchronization will have to be done by the client, it saves file transfer time and makes engineering a same-day job realistic.
Hopefully, if the client really needs the work done the same day, this is a viable solution, and even with fast connections this is a great way to work, based on the time you can save messing with transfers. If not, you're left waiting for a potentially very large video file to download via the 'net, then you do the work, then you send it back with the audio... which is ultimately an even LARGER file. If you or your client's connection is slower than cable/DSL (you might just sneak by with ISDN), you could be looking at truly prohibitive download times. Even with those services, really large hi-rez video files could take a good portion of your day just to download. For those situations, Fed-Ex is still a widely used option. Of course, if you wanted to more or less nullify the bandwidth issue, get a T1 or T3 line! That's what the big boys do.
