Mash YouTube Videos

Omnisio lets you paste in the URL of a YouTube video (among other video sites) and then crop the time slider to a specific part. You can then add more videos if you want, and publish the result to show to others – without even registering at the site, a cool approach. The site is fairly straightforward to use and all in all well done, albeit the editor interface is unnecessarily confusing*, and there seems to be a bit of a lack of available effects (like fade in/ fade out, color effects, text overlays and such).

Note that, YouTube also has an online video editor (with some issues, though).
Also, Google Video allows you to directly link to a certain part within the video by appending e.g. #4m12s (the minutes and seconds into the video) to the video URL.

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