Trim, edit and convert any audio or video file: 123apps
123apps is a free set of online audio and video editing utilities. The tools are very easy to use and they interface directly with Dropbox, Google Drive and Skydrive to open and save your files.
The Video Cutter tool makes it very easy to trim a video by eliminating and cutting out specific sections of it.
The Video Converter offers a very good set of supported video file formats and options to control resolutions, audio and video codecs and file size/compression.
The suite also includes:
Audio Cutter
Audio Joiner
Audio Converter (also available in a PRO version)
My comment: Excellent cloud-based suite of apps for basic audio and video editing and conversion needs. Works with both video and audio URLs and files that you upload. Easy, free and useful. Ad-supported. Highly recommended.
Try it out now: http://123apps.com/