NetBeans IDE & Eclipse IDE are the best two environments to work for developing JavaME applications.
The only difference which I found out between the two IDE when I coded on JavaME was that for NetBeans , J2me environment was already added.
For Eclipse , the developer was required to add the j2me plugin , antenna for building , J2me Wirless toolkits
NetBeans IDE can be downloaded from the following link
http://netbeans.org/features/javame/
Eclipse IDE & EclipseME plugin can be downloaded from the following links respectively
http://www.eclipse.org/downloads/
http://eclipseme.org/