I like the look of dashboard in mac with all the widgets. After searching here and there, I found out that we can achieve almost the same thing with Ubuntu. What you need to do is:

1. Install screenlets
   sudo apt-get install screenlets
2. Install compiz config setting manager (if you haven’t)
   sudo apt-get install compizconfig-settings-manager
3. Run Compiz config manager
   System -> Preferences -> Compiz config setting manager
4. Go to catagory Desktop then enable widget layer
5. Close Compiz config
6. Open screenlets
   Applications -> Accessories -> Screenlets
7. Start the screenlets you want to use
8. Go to the properties of all running screenlets -> Options -> Check the “Treat as widget” checkbox
9. Now you can look at your dashboard by pressing F9

If you have problem with the weather screenlet, check this out, maybe it can help.