YouTube smacks down 3rd party download sites
Looks like sites such as ClipNabber, SaveVid, KeepVid, and others are hurting after recent changes by YouTube to its infrastructure. The recent changes prevent such sites from providing links to their visitors to download videos from YouTube.
Google has made similar moves in the past to disrupt such sites, but in the past the download sites have always found a way around the moves pretty quickly. However, it seems that this time, they may have finally been stopped from business as usual.
Other than using this bookmarklet, it seems that the only other choice for convenient YouTube downloading is now to install software of one type or another. (Less conveniently, there are other ways to download the files with no software, but its a bit of effort.) SaveVid, YouDDL, and KeepVid now require users to install a Java applet. There are handful of companies also pushing desktop software solutions. However, I carefully avoid desktop software or Java applets from any site that I do not fully trust.
There are of course some popular browser add-ons and extensions that work, but my favorite option, as you may have guessed, is a bookmarklet; specifically this bookmarklet to directly download videos from YouTube, DailyMotion, and FaceBook