File/Export/Using QuickTime Conversion; set to preset for the web (multimedia), and keep in mind that the medium and low broadband settings drop frame rates down. I suggest high bandwidth setting, of course the person on the other end will need quicktime to view. A 3 minute vid should compress down to under 20MB, but you may need to tweak the audio setttings using the options button. I recommend setting the audio to AAC @ 128kbps, or lower if it's just talking (no music or hi-fi sounds). That should give you a good quality output.
Otherwise, export the full video at full resolution (.mov), then open in iMovie, then choose the Share/send to iTunes or Share/save to disk, and use iMovie's settings in the dialogue window to set for the web.