Copy Clipper for Chrome
More About Copy Clipper
It makes youtube urls short, amazon urls short, strips off the GA tracking parameters that reader/feedburner puts on urls and is driven by regexp search/replace.
If it ever clips something you don't want clipped, you can click Undo in the notification window and it will restore the original value.
It didn't have to be a chrome extension, but I like the easy UI for an options panel, and the auto updating from the chrome store is neat.
It's a bit like this extension: https://chrome.google.com/webstore/detail/kcpnkledgcbobhkgimpbmejgockkplob
but the urls don't have to hit the url bar/omnibox before they are trimmed.
* support for new Chrome Notifications
* regexes are synced across browsers using chrome.storage.sync