"If you're finding the iPhoto portion a bit tedious you can try a program such as Clipstart which focuses completely on movies but you'll still have to import it into iMovie.
Unfortunately at present there is no seamless way to get the videos from the iPhone direct to iMovie without first stopping off in iPhoto."
Connect iPhone 3GS using iPod cable. Launch Image Capture app. Select movies/images to import. Launch iMovie and use File > Import > Movies... and browse to folder where you saved the movies.
Okay so I admit this is just substituting iPhoto with Image Capture, but the latter app is much more lightweight I guess... but then again if you use iPhoto then all your imported iPhone movies become available in the 'media browser' for other apps in iLife/iWork.
