Wanner Create a widget for fun and learning,
Just Know that the image is re-sized incorrectly
According to http://developer.android.com/guide/practices/screens_support.html
The Nexus One has a DPI somewhere around 250 which puts it into the hdpi class. Using the google formula of (number of cells * 74) - 2 to calculate dp for your 1x1 widget would make the widget dimensions 72x72 dp.
The conversion from dp to pixels is:
pixels = dp * (density / 160)
So for a 72x72 dp image, the corresponding image sizes based on density would be:
ldpi (120 DPI) = 72 * (120 / 160) == 54 x 54 pixels
mdpi (160 DPI) = 72 * (160 / 160) == 72 x 72 pixels
hdpi (240 DPI) = 72 * (240 / 160) == 108 x 108 pixels
Use these formulas to create your assets and you should get crisp images.