The latest version of Real Player allows you to download video clips from the web in one click. To enable this feature, click on Tools/Preferences and Download & Recording.
Now when you visit a page which contains a video clip, the tab Download this Video should automatically appear. Clicking this launches the RealPlayer Download & Recording Manager dialogue box. Click on View My Library, find the file and right click it. Click Locate File which will take you to the folder where the clips are saved by default.
To check what file type the clip is, right click it, select Properties and look next to Type of File. If it is a FLV file, you can download this FLV player to play it or convert the file format using a site like Zamzar so you can embed it into PowerPoint, play it through Windows Media Player or watch it on a mobile phone.
It goes without saying that you shouldn't download any clip which is covered by copyright.
Here is a clip I downloaded today from the first Flashmeeting I ran on blogging and podcasting where Alex Blagona from Northgate High School in Ipswich explains how he moblogged with his Sony Ericsson K750i phone in France recently. A real highlight of the evening.