In creating the .MOV file, I accepted the QuickTime Pro defaults of Medium quality video and uncompressed audio. The resulting file is 36.6MB in size. For 1 minute of 320x240 video, that's huge!

Next up, I switch the export option in QuickTime Pro to MPEG-4. The default settings are Video Track: Improved; Size: 320x240; Audio Track: Music. The resulting file size is 7.5MB, which is definitely acceptable for directing grandparents and friends to movies of the kids.

Depending on when and how QuickTime was installed (or if it was installed), Windows users may find it difficult to watch your .MP4 video. My default configuration of QuickTime, pre-installed by HP, did not have .MP4 associated with QuickTime which meant downloading .MP4 files resulted in a file unrecognized by the system. This is easily remedied by opening the QuickTime preferences and adjusting the file associations, but that probably means more family tech support.

If you prefer to use an alternative .MP4 player, be prepared to get emails from people who can watch the video but can't hear any sound. The QuickTime .MP4 output uses AAC audio by default, which is unsupported in any other player, without additional codecs. You can solve this problem by having the viewer download the 3ivx codec pack and a companion AAC parser, but that's asking a lot of people who might not be computer savvy.

Converting the file to WMV format automatically means the greatest number of people will be able to view the file. In the case of your .MOV file, you'll need to use QuickTime Pro to export the movie as an .AVI and then convert the movie using Windows Movie Maker or the Windows Media Encoder. This requires an extra step, but remains the easiest way to share movies with people who aren't inclined to download additional software. In my test case, Windows Media Encoder produced a 4.51MB WMV, which is the smallest output in the test.

Another alternative would be to output DivX content. Using the DivX Portable Device Profile in Dr. DivX, which outputs 320x240 video files, results in a file size of 4.95MB, which is only slightly larger than the WMV file. DivX has the advantage of being playable on Linux, Mac OS X, Windows, and a number of portable devices. Dr. DivX supports importing .MOV files natively, so there is no need to convert to .AVI with QuickTime prior to the transfer. The downside to the DivX is users will need to have a DivX compatible codec installed on their machine in order play the file, which is what you were trying to avoid in using QuickTime .MOV files. Fortunately, the DivX codec is very easy to acquire, either directly from the DivX download site, or by installing a compatible alternative like ffdshow, which also bundles other useful codecs.

Which format you choose is ultimately up to you. Obviously, the .MOV file format is the largest of the bunch, producing file sizes several factors larger than all three alternatives presented here, without a discernable quality benefit. If most of the people who will watch your movie are Windows users, it may be worth the extra steps to make the video easily compatible with their needs and convert the file to WMV. On the other hand, if your primary criteria is making the file size smaller than the MOV, using MP4 and reminding people to download QuickTime is certainly the easiest route for you.

Comparison of video output options

Original AVI	1536 kbps	720x480	29.97 fps	176MB
MOV	624.5 kbps	320x240	29.97 fps	36.6MB
MP4	127.5 kbps	320x240	30.00 fps	7.5MB
WMV	677 kbps	320x240	29.97 fps	4.51MB
DivX AVI	84 kbps	320x240	29.97 fps	4.95MB