Via Fred by way of Erik, Sparta is an open source XML parser for J2ME recently released as open source by HP Labs. It implements a DOM and is not written for J2ME in particular. However, using Sparta in a J2ME environment should present no problems. Sparta implements XPath, and I’m excited about the possibility of XPath in my pocket.
kXML and kXML2 are also options. They are both J2ME specific.