For much of the past decade, attempts to corral the explosion of new metadata schemas (or formats) have been notably unsuccessful. Concerns about interoperability in this diverse and rapidly changing environment continue, with strategies based on syntactic crosswalks becoming more sophisticated even as the ground beneath library data shifts further towards the Semantic Web. This paper will review the state of the art of traditional crosswalking strategies, examine lessons learned, and suggest how some changes in approach--from record-based to statement-based, and from syntax-based to semantic-based--can make a significant difference in the outcome. The paper will also describe a semantic mapping service now under development.