If you like the widgets in OS X, but you don't have a Mac, you're not left out.

If you're a Windows user and you haven't seen Yahoo Widgets they will give you the eye candy you desire. It's free and has tons of widgets to choose from. Yahoo widgets also has a OS X version and Mac is where this application began. It used to be called Konfabulator and was around before Apple built widgets into it's desktop.

Don't worry if you're a Linux/Unix user your not left out. Superkaramba for KDE is an awesome Python based widget engine so it has a lot of power. There is a good selection of widgets for Superkaramba on KDElook.

For Gnome users check out gDesklets. gDesklets is also Python based widget engine. The selection of widgets isn't very big as it fairly new, but Gnome-look now has an entry and we will see more soon I am sure.

I use Superkaramba and honestly, I don't think I could live without it now. I get Kubuntu security warnings and news right on my desktop, monitor my system, and keep tabs on the weather without having to open a single app.

My wife uses some of the Mac widgets, but I never understood why you have to lock your main system out to get to them. I think Yahoo Widgets is a better idea since I can use them while working.

Here are some more alternatives. I don't really consider these widgets, but they are nice system metering applications some with multiple features, like weather, etc...

Linux: gKrellm

Windows: Sysmetrix , Rainy(maybe dead) , and Samurize

OS X: Gaucho XRG  and MenuMeters