Like most people here I have a lot of Dashboard Widgets. Problem is that a) having everything open is not an option and b) finding which one you need can be annoying at times. Due to these restrictions I find I use Dashboard not as often as I should/could.
The make better use of my widgets, this is what I do now: I now only search and activate widgets via Launchbar (Quicksilver/Butler/Spotlight are options as well). After use I close the widget.
Here a movie of how it works - hope you like it!
Easier use of Widgets