Dashboard disabler! I confess I don't usually have OS X's Dashboard active on my Mac. In fact, I actually disable it with Disable Dashboard Utility - 1.0! Most of my needs are a click or two away on the net as Quicksilver and Drag Thing can call up applications, utilities, bookmarks and URLs. And Transmit has droplets!
Combinations monitor situations But a combination of widgets can provide a grasp of a situation, e.g. during a space shuttle mission when I put a few simple widgets together and watched the launch. I was fascinatd that we could watch that launch on any laptop with wireless access.
Useful to travellers Dashboard widgets can be useful when traveling - they just helped me monitor weather and news in Newark to provide Ladybug with info when she was held up there while returning from Boston. The flight times are an hour behind though.
The doppler radar provides a regional weather perspective (green stuff is rain). There is a moon phase in there (all dark as its a new moon), and the tide gauge is very useful in planing shore trips or if you're worried about floods!
Local content You can see I was monitoring news about the northeast US floods so I placed the MSNBC news widget over local content - Straits Times Interactive and Tomorrow.sg (by none other than Kevin Lim). If you have configured your Yahoo! page for local news, use My Yahoo! Widget. There was a Street Directory widget but its gone MIA.
Windows too! Widgets are not just for Mac users - Yahoo has Yahoo! Widgets for Windows users too since Nov 2004. It all originates from the pre-Tiger Konfabulator.
Another tool in the toolbox Despite my infrequent use (a few times a year), I have sufficient familiarity so it just takes seconds to add widgets; this is useful in times of urgency, so play with it a little now. Its also important to realise that widget-provided information is just a primer. Talking to people is still critical!
I took a screenshot before I disable Dashboard once more. Its recommended that Dashboard be enabled before an OS X update.