Here's two tips for the new iTunes 10 that you might not have seen yet. First up, 9to5Mac shares the news that you can now plug any iOS device with music on it into iTunes 10 and listen in to whatever music is available without having to enable "manual sync mode." That's a nice bonus -- if you're at a party, and your friend wants to hear a tune you're carrying around on the iPhone, you can just plug it in, hit play, and dance the night away. I presume all of the usual restrictions on sharing music are still there (music bought on one account can't be downloaded to another, obviously), but at least just for listening, iTunes 10 makes things much easier.
Mac OS X Hints also shares a tip for those disappointed by the look of the grayed-out icons in the iTunes 10 sidebar. By putting a certain line into Terminal, you can enable "high contrast mode" for the app. It won't bring back the colors (it basically just inverses the sidebar from black-on-white to vice versa), but if you need a little more action in the iTunes sidebar, you can give it a shot.