The PathSBML plugin allows researchers to visualize and overlay data on the same pathway models they use in simulation experiments. Exporting these models as GPML would also allow them to be uploaded to Wikipathways for community curation.
This plugin connects to the online pathway databases, WikiPathways, and allows users to search and browse pathways from PathVisio directly. It also enables updating and upload functionality (special permissions are required which can be requested from the WP developers).
This plugin allows users to export and import pathways in BioPAX format. The plugin support BioPAX level 3. The import functionality is limited (pathways might need manual rearranging of objects).
The MAPPBuilder plugin helps you get started quickly on creating a new pathway. Given a list of gene identifiers, MAPPBuilder will build a simple prototype pathway for you containing those genes, eliminating the step of manual searching for each gene/gene product you want to include.