safarivlcyoutube
The usual way for downloading youtube's flv files used to be to double-click on the conspicuously largest file in Safari's activity window (cmd-option-a).
For some reason doing so now triggers viewing the video using a plugin. The possible culprits are perian and vlc. Disabling perian doesn't help, and vlc does not seem to include a plugin. What to do?
I don't use it, but GLIMS looks like it will easily let you insert a search engine different than what Safari bundles.
More intrusive, but way slick in my opinion is the SafariOmnibar it's excellent work and you can customize your search provider since it's hacked into that part of safari using SIMBL - the SIMple Bundle Loader process.
I use LaunchBar and search from a keyboard shortcut - it allows extensive control over searching - you can define custom search sites and criteria easily. It has many other features (notable extremely quick app and file launching as well as a clipboard history) but it's so fast you might like it just for getting a UK search if nothing else fits your needs.
In Safari > Preferences > Tabs, there's a preference for setting when pages should open in windows or tabs.
Look here:
This will force every application to open links in tabs.
Best Answer
Hold Option while you double click on the file to force it to download instead of play. If you have something downloading already (or are using an older version of Safari), you can also copy from the activity window and paste into the downloads window.