z4root is a one click solution to root and un-root your device. However, it does not work for NAND locked devices.
http://droidbar.net/2010/11/one-click-root-with-z4root/
Supported Devices
Dell Streak
Garmin-Asus A50
HTC Dream
HTC Hero
Huawei Ascend (Cricket Wireless)
Huawei U8120
LG Ally
LG Optimus T
Motorola Backflip
Motorola Cliq
Motorola Defy
Motorola Droid
Motorola Droid 2
Motorola Droid X
Motorola Flipside
Motorola Milestone 2
Samsung Acclaim
Samsung Galaxy 3 I5800
Samsung Galaxy I5700 Spica
Samsung Galaxy S (All Variants)
Samsung Galaxy Tab
Sony Ericsson Xperia X10/X10 Mini/X10 Mini Pro
http://droidbar.net/2010/11/one-click-root-with-z4root/