This week I'm going with an oldie but goodie that I use every day. Way back when Dashboard first appeared, my biggest problem with it was that I simply forgot about it. My main use of Dashboard is for displaying information that I want to remember, e.g. appointments with iCal Events, iCal ToDos with DoBeDo, the weather, etc. However, for this to be really useful it needs to be in front of my face a lot. And since I generally tend to forget to invoke Dashboard on my own this pretty much fails.
Enter the basic preference pane app Dasher, which does one simple, but amazingly useful thing: it automatically invokes the Dashboard after a set period of time. Everytime I step away from my Mac and return, the Dashboard is displayed with my appointments, etc. so that now they're in my face enough for me to remember them and Dashboard finally works for me.
Dasher is a free download from Splasm Software. It's an old piece of software that has not been updated in quite some time, but it still works fine on my 10.5.7 machine.
Incidentally, there's another way to accomplish something similar using an OS X screen-saver. DashSaver (donation requested) from High Earth Orbit installs as a standard screen saver and will also display the Dashboard after a set period of time.