Make an omelet, tie a bowline, get a cork out of the inside of a wine bottle.
WTOP recently had a segment on the use of online video clips to learn how to do various things. We once had a reference question - how to tie a bow tie - that sent us in desperate search of good illustrations. So to assess various how-to sites we tried the bow tie question.
WikiHow You can both edit and add your own material. This is a collaborative group effort which sometimes leads to odd writing. The instructions on to get rid of house flies at a picnic suggest that one stick clover seeds into an apple. Surely they mean cloves ? The bow tie entry is excellent - clear instructions with illustrations and a link to a video. (They also have photo-illustrated instructions on how to make a pumpkin pie using an actual pumpkin, which was a reference question this week.)
eHow As with WikiHow this is mostly text and the quality of any entry depends upon the care and skills of the creator. However don't ignore the rough ones - this may be a wonderful way to archive folk knowledge. The bow tie entry is a bit hard to find, but is illustrated with photos.
Do-it-yourself reference. AnswerBlog. Someone asks a question, others try to answer it. Some of the people answering questions know what they are talking about, others do not. As with the above sites, it has all the pros and cons of the uncredentialed, collaborative approach. As for the bow tie question, it was asked and the answer is a link to a tie site. Not nearly as useful as the entries in WikiHow and eHow.
ViewDo Videos only. No entry for bow tie. Anyone can contribute videos, but this is much more limited than the sites above because fewer people have the means to make and post short videos. Presumably it will grow. Meanwhile you can learn to French braid hair.
The British National Archives are putting their informational films on line. 1945 to 2006, and lots of fun. Not the sort of site to search with a specific question, such as tying bow ties, in mind. But great for social history. No bow tie how-tos, or none that were easily found. However you can dig up interesting portraits and photographs by doing a general archives search, as you can with the American Memory colletion. (Emmaline Pankhurst.)
Remember that "how does one tie a bow tie" is just one of the many questions that might be searched two ways: bow tie and bowtie. We just used bow, as we were already within restricted databases at each of the sites, not searching the web.