While searching on Brightcove, a video search and aggregation site - like YouTube, but with longer form videos - I came across a number of interesting Sherlock Holmes-related findings. Brightcove hosts its own content (powered by AOL Video), plus it links to other sites that host videos, giving you a wide range of stuff to choose from.
There were a number of the Basil Rathbone / Nigel Bruce films available for download. But more interesting to me - because the videos are less common and because of the lead actor's uncanny resemblance to some of the illustrations of Holmes (Frank Wiles in particular) - were the Arthur Wontner films. I've previously written about the availability of some of these through the Internet Archive, but this was the first time I had seen 3 of the 5 Wonter films available in such a shareable format. The first two Wontner films are unavailable - there are no known prints existing of The Missing Rembrandt (based on "Charles Augustus Milverton"), and The Sleeping Cardinal (based on "The Final Problem") was thought to be lost until a print was discovered in the U.S.
Feel free to watch the three here (note: you need to have Flash installed), download them directly from Brightcove, or to purchase your own copies through Amazon.