Apple has thoroughly neglected Dashboard for a long time now, but it can be extremely useful and fast -- and I would argue it's faster and less disruptive to bring up than that narrow Notification Center window, and it definitely has WAY more real estate to show more things. Dashboard still has a ton of potential, but frankly nobody knows it's there, and new widgets are not really being developed for it.
1. make sure (in the Mission Control preferences) you set it to display As Overlay, so it leaves everything you're working on untouched and just appears as a very quick heads up display. Hit F4 to quickly view it, and hit F4 again to dismiss it immediately. Whatever you were working on is still right there. The default "As Space" setting is much more jarring.
2. reclaim the useless Launchpad key to launch Dashboard instead. (personally, I launch everything from Alfred or the Dock anyway). I use a little control panel called Function Flip to map F4 back to Dashboard.
3. remember that anything you view in Safari can be "clipped" as a dashboard item. I use it for some clippings of weather radar, for example, that are just a keystroke away. Just go to File > Open in Dashboard, and then it will prompt you to draw a box around whatever you want.
I use it for a package tracking app that syncs with my phone, a few world clocks for phone calls, and a big system info widget. If there were more widgets, I'd definitely use them.
