[john.gersh]

Omnigraffle does export documents to html. The resulting set of files implements OG actions for jumps to canvases within the document and for opening external URLs.

Export your document (File->Export) and choose "HTML image map" in the Format pulldown in the resulting file chooser. For what you're doing, make sure Export Area is Entire Document.

The result is a folder containing an html file and an image file for each canvas. Each html file contains an image map in which the links point to other canvas pages or to external URLs.

The links to other canvas pages are relative; make sure that all the files stay in the same folder when you upload them.

You can also link to other documents that can be opened in a browser, but it's a little trickier. Since OG creates relative links to them, they also need to be in the folder it creates in the export. You'll have to put them there yourself after exporting. Of course, you can also edit the html after the export to have the links point wherever you like.