Ever get the message, "Phone storage running low"?

Here is what to do on the original Droid:

Go to the home screen, and press the menu button, then go into "settings".
From the main menu press "Applications"
Then press "Manage Applications"
Then press the menu button again and you will get the option to "sort by size", press that.
Now starting at the top of the screen and listed in descending order are your applications and how much space they are taking up.
Not playing the Christmas version of Angry Birds anymore?  Delete it!
Assassin's Creed demo run out of time? Delete it!

Another trick is to go into your phone app, press "Call log" at the top of the screen, then press the menu button and you should get an option to "Clear call log"....press it.  Amazing how much space that takes up.